Leaf Litter Invertebrates of the Morgan Arboretum

Invertebrates, while small, play an integral role in our ecosystem in the St. Lawrence Lowlands. In leaf litter, they aid greatly in the decomposition of organic matter, as cited by Vasconcelos and Laurance in their article on soil fauna (2005).


A European Ground Beetle (Carabus scrutator) found in the Maple forest leaf litter

Invertebrates are animals that lack a backbone, but this is where most of the obvious commonalities stop. They make up over 90 percent of all the animals on earth, and are a very diverse group. With more than 35 phyla, they can be found all over the planet, with marine, aquatic, and terrestrial representatives (Invertebrate, 2015).

Soil- and litter-dwelling invertebrates, which are the focus of our research, consist mainly of the phyla Annelida, Arthropoda, Mollusca, Nematoda, Rotifera, and Platyhelminthes. These are all relatively small, from less than a millimeter to a few centimeters in length (Franklin & de Morais, 2006).


A millipede (Class: Diplopoda) (right) and an earthworm (Class: Clitellata) (left) help nutrient cycling in forest floors by breaking down organic matter and making it available to plants

These little critters play an important role in the cycling of organic matter, which is vital for the forest ecosystem to persist (Berg, 1986). The decomposition of leaf litter is especially important, as these nutrients can make up to 72% of the aboveground nutrients returned to trees (Fogel & Cromack Jr, 1977). The soil- and litter-dwelling invertebrates do this by consuming leaf litter and other dead plant material, and decomposing it into nutrients available for the surrounding biota (Berg, 1986).

Since invertebrates affect and interact with soil, surrounding plants and animals, they are important and effective biological indicators for changes in soil properties and ecosystem health (Franklin & de Morais, 2006).



Our Project:

Research Question: What difference exists in invertebrate diversity between coniferous hemlock forest floor and deciduous maple leaf litter?

To tackle our question, we went to the Morgan Arboretum, which offers a wide variety of forest types with 18 different collections of trees and shrubs from around the world (Arboretum, 2011). There, we chose a pure Sugar Maple (Acer saccharum) forest, and another plot dominated by Hemlock (Tsuga canadensis).


arbomap_trails :Locations of Hemlock and Maple tree stands at the arboretum where 4 sites from each forest type were chosen and sampled.


In both the Maple forest and the Hemlock forest we set up 4 1×1 meter plots, placed randomly within the forest sections. The leaf litter found in these plots was gathered and sifted in situ, using a Winkler sifter. The litter was sifted over white trays, making it easy to spot any invertebrates hiding in the litter. The bare topsoil left in the plot was searched by hand. Any invertebrates found were collected and brought back to the lab for later identification.


Leaf litter from the Hemlock forest being sifted, using a Winkler sifter, into white trays where any invertebrates can be readily spotted and collected


We noticed that the Hemlock forest’s sparse forest floor was humid, shaded, and covered with needles. Conifer forests tend to have more acidic soil, with a lower pH due to the persistence and decomposition of coniferous needles (Turk, Schmidt, & Roberts, 2008).


Sparse coniferous forest floor


The Maple forest was the opposite; it had a thick (5-10cm) covering of colourful leaves. The soils of deciduous forests, such as this Maple forest, tend to be less acidic than that of the conifer forest (Turk et al., 2008).


Un-sifted, colourful Maple forest floor (left) and our sifted workspace (right)


Characteristics of the forest floor, including pH, humidity, and the composition of the leaf litter have a strong influence on what invertebrates will live there (Burghouts, Ernsting, Korthals, & De Vries, 1992). We were curious to see if the needle-filled, acidic Hemlock forest floor fostered different invertebrates than the leafy, nutrient rich Maple forest floor, and to what degree.

From observation alone, it appeared as though there was greater biodiversity in the deciduous Maple leaf litter. We noticed that the Hemlock forest consisted mostly of predaceous specimen while the Maple forest contained a wide variety of phytophagous (plant eating) invertebrates and detritivores. Our team concluded that these might be explained by a few related factors. For one, decomposition of needles leads to a lower soil pH, which reduces the ability of many plants to grow. In addition, slow turnover rate means plants have limited access to the nutrients that are present.

Invertebrates living in coniferous forest floors must be adapted to the harsher conditions of soil and vegetation, or find their nutrients from other sources. Selection would favour predators rather than plant or detritus feeding invertebrates.

We also noticed that specimens collected in the Maple forest were consistently larger than those found in the Hemlock forest. Nutrients limit growth, so we deduced that the size gap was also consequence of richness of leaf-litter. In contrast to the Hemlock forest, the Sugar Maple forests’ nutrient abundance allowed for the development of larger invertebrates, like the stink bugs and ground beetles.


Stink bug (family: Pentatomidae) found in Maple leaf litter



Arboretum, M. (January 2011) Retrieved Oct. 29 2015, from http://www.morganarboretum.org/arboretum/the-tree-collections.html

Berg, B. (1986). Nutrient release from litter and humus in coniferous forest soils—a mini review. Scandinavian Journal of Forest Research, 1(1-4), 359-369. doi: 10.1080/02827588609382428

Burghouts, T., Ernsting, G., Korthals, G., & De Vries, T. (1992). Litterfall, leaf litter decomposition and litter invertebrates in primary and selectively logged dipterocarp forest in Sabah, Malaysia. Philosophical Transactions of the Royal Society B: Biological Sciences, 335(1275), 407-416. doi: 10.1098/rstb.1992.0032

Fogel, R., & Cromack Jr, K. (1977). Effect of habitat and substrate quality on Douglas fir litter decomposition in western Oregon. Canadian Journal of Botany, 55(12), 1632-1640. doi: 10.1139/b77-190

Invertebrate. (2015). In Encyclopædia Britannica. Retrieved Oct. 29 2015 from http://www.britannica.com/animal/invertebrate

Franklin, E. & de Morais, J.W. (2006). Soil Mesofauna in Central Amazon. In F. M. S. Moreira, J. O. Siqueira, & L. Brussaard (Eds), Soil Biodiversity in Amazonian and Other Brazilian Ecosystems. (pp. 142-143) Wallingford, Oxfordshire, GBR: CABI Publishing.

Turk, T. D., Schmidt, M. G., & Roberts, N. J. (2008). The influence of bigleaf maple on forest floor and mineral soil properties in a coniferous forest in coastal British Columbia. Forest Ecology and Management, 255(5), 1874-1882. doi: http://dx.doi.org/10.1016/j.foreco.2007.12.016

Vasconcelos, H. L., & Laurance, W. F. (2005). Influence of habitat, litter type, and soil invertebrates on leaf-litter decomposition in a fragmented Amazonian landscape. Oecologia, 144(3), 456-462. doi: 10.1007/s00442-005-0117-1


Shelf Fungus Diversity and Tree Health at the Morgan Arboretum

picture 1

A great diversity of shelf fungi can be seen on this rotting log


The importance of shelf fungi in the St-Lawrence lowlands

Polypores (also known as Shelf fungi and Bracket fungi) are found across North America, anywhere woody plants are present (Gilbertson, 1980). They usually grow on fallen logs, stumps, dead branches and even living trees whose bark has been breached and begins to decay (Roberts and Evans, 2011). They have a wood-like, almost leathery texture, and produce spores under their caps. Most of them are wood-rotting and therefore inflict serious damage to their hosts (K. McKnight and V. McKnight, 1987). Polypores that degrade hardwood are a problem for the lumber industry, as they lead to economic losses. However, bracket fungi are of great importance to the St-Lawrence lowlands ecosystems. Indeed, they recycle carbon by degrading cellulose from the tree bark and returning it to the atmosphere. They also allow old trees to weaken and fall to the ground, where they decompose and become important components of the soil. This allows young healthy trees to take their place, as part of the forest regeneration process. Moreover, polypores are crucial to wildlife, as they provide habitat for various species. Birds nest in the cavities they form and arthropods as well as small amphibians find shelter within their fruiting bodies (Gilbertson, 1980). Shelf fungi are very diverse, and we observed many genus during our research project in the Morgan Arboretum. Turkey Tail, Redbelt, Hen-of-the-Wood and Dryad Saddle are among the most abundant and noticeable types of fungi we encountered (K. McKnight and V. McKnight, 1987).

picture 2 (1)

Clockwise; (starting at top left) Turkey Tail, Hen-of-the-Wood, Dryad Saddle, and Redbelt fungi

Vulnerablity of trees to environmental factors

Forest composition fluctuates in response to changes in climate as well as different nonnative biotic stressors such as diseases, pests and invasive plants. The association of two or more of these factors can exacerbate population declines in some tree species as well as hinder the growth of others (Fisichelli et al., 2014).
Certain trees exhibit a higher vulnerability to these ecological strains than others. A particularly striking example is the American beech tree, Fagus grandifolia, which is plagued by beech bark disease. This blight is caused by beech scale, Cryptococcus fagisuga, which attacks bark and renders it vulnerable to fungi infestation. The invasion of the wood by fungi of the genus Nectria is deadly to the tree (Houston and O’Brien. 1983).

The disease has severely impacted the composition of North American hardwood forests, where the beech tree is a founding species. The decline in beech tree populations is detrimental to certain species and therefore alters biodiversity (Cale et al., 2013).

picture 3 (1)

A fallen beech tree with Polypores

The effects of shelf fungi on trees

Trees, regardless of the species, are vulnerable to fungal diseases when their protective outer bark layer is breached. The wound may form due to insect pests who consume the bark or use stylets to access nutrients deep within (for example, sugar maple sap), or animals who scratch the surface, peck it or feed off of it. Humans tend to carve their initials into bark for amusement purposes or expose the bark when trimming the tree and breaking off branches. Once the bark is damaged, the fungus’s spores have an entryway into the woody internal flesh and begin to thrive (Fogal 2006).

As it is extremely pervasive, it is impossible to clear a tree of a fungal infection. This is due to fungi’s composition of filamentous fibers called mycelium, which provide strength and stability. Mycelium hook onto the fibers of the wood and feed off it. By secreting enzymes, they break down wood fibers into cellulose and lignin components, which results in the degradation of the timber. From the wound, the fungus spreads internally and rots the inside of the tree. New cracks on the outside of the tree appear and allow entry for more fungi of the same or different species. The dead tree may remain standing or fall, but either way, the fungus will continue to thrive and work as a community to decompose it until there is nothing left but decayed matter (Ross D.R., n.d)

Our project

picture 4 (2)

Map of the Morgan Arboretum showing the two study sites, characterized by dominant forest type

Within the Morgan Arboretum, we conducted half of our research in the sugar maple stands and half within a mixed beech and red maple forest (as there are no pure beech stands in the Arboretum). In total, we located 40 trees of the American beech and sugar maple species that bore shelf fungi. Our research spanned three weeks, during which we made two trips to the field. On Monday October 5th, we studied 20 standing or fallen sugar maple trees for shelf fungal growth. On Monday October 19th, we inspected shelf fungus specimens on 20 American beech trees.

Upon venturing off the path, all five of us walked in different directions to allow an unbiased selection of our sample trees and to increase the variety of our outcomes. Every time we located an infected tree or log, we tied a pink marker around it to avoid repetition. Then, in an Excel spreadsheet on our portable tablet, we recorded the species, color, average diameter, and abundance of the fungi. We also assessed the tree’s health through the following criteria: approximate percentage of leaves, bark health (presence and abundance of cracks, peeling, scars, rot, etc), general health of the tree (fallen, standing, or diseased), and presence of beech bark disease.

picture 5 (1)

Pictures must be taken at several different angles to help with identification

A selection of fungi guides, including A Field Guide to Mushrooms: North America by Kent H. McKnight and Vera B. McKnight and The Book of Fungi by Peter Roberts and Shelley Evans, were of great help in identifying species of shelf fungi found in the Morgan Arboretum. The team’s field knowledge, coupled with our photographic evidence, enabled us to discern the color, shape, texture, size, and distribution of the shelf fungi. Referring to the literature, armed with our data, we then successfully classified the specimens. However, identifying fungi is no easy task due to its vast diversity and many resemblances between certain species of shelf fungi like Turkey Tail and the Multicolor Gill Polypore. Photographing the fungi from many angles, including the underside, gives a whole new perspective on each fungi and helps in the identification of the species.

picture 6 (1)

Flagging tape was used so that trees were not counted twice and to promote our twitter account

Our analysis of the data collected reveals interesting trends between different varieties of shelf fungi and their impact and relationship with the sugar maple and American beech. We determined that there is a greater diversity of shelf fungi on American beech trees as compared to sugar maple trees. This raises questions about how fungi affect the health of trees, given that the American beech trees in the Morgan Arboretum are generally in poorer health than the sugar maple trees.




Cale J, McNulty S, Teale S, Castello J. March 2013. The impact of beech thickets on biodiversity. Biological Invasions. [accessed 24 Oct 2015]; 15 (3): 699-706. http:// link.springer.com/article/10.1007/s10530-012-0319-5/fulltext.html doi:10.1007/ s10530-012-0319-5.

Fisichelli N, Abella S, Peters M, Krist Jr. F. September 2014. Climate, trees, pests, and weeds: Change, uncertainty, and biotic stressors in eastern U.S. national park forests. Forest Ecology and Management. [accessed 25 Oct 2015]; 327: 31-39 http://www.sciencedirect.com/science/article/pii/S0378112714002722
doi: 10.1016/j.foreco.2014.04.033

Fogel, Robert.14 Nov 2006. Shelf fungi. Fun facts about fungi. [accessed 26 Oct 2015]. http://herbarium.usu.edu/fungi/funfacts/shelffungi.htm

Gilbertson, Robert L. Jan-Feb 1980. Wood-Rotting Fungi of North America. Mycologia. [accessed 26 Oct 2015]; 72 (1): 1-49. http://www.jstor.org/stable/pdf/3759417.pdf? acceptTC=true or http://www.jstor.org/stable/3759417?seq=2#page_scan_tab_contents. doi: 10.2307/3759417

Houston D and O’Brien J. 1983. Beech Bark Disease. U.S. Department of Agriculture Forest Service. (Forest Insect and Disease Leaflet 75); [accessed 26 Oct 2015]. http:// http://www.na.fs.fed.us/spfo/pubs/fidls/beechbark/fidl-beech.htm

McKnight, Kent H. and McKnight, Vera B. 1987. Mushrooms. Roger Tory Peterson. Boston: Houghton Mifflin Company.

Roberts, Peter and Evans, Shelley. 2011. The Book of Fungi. The University of Chicago Press. London: Ivy Press.

Ross, D. R. Conks/Shelf Fungi. State of Alaska: Department of Natural Resources. n.d. [accessed 26 Oct 2015]. plants.alaska.gov/pdf/Conks.pdf



Chickadee Abundance in Response to Human Presence at the Morgan Arboretum

Appearance and Identification:

Black-capped Chickadees (Poecile atricapillus) are well-known songbirds, loved by everyone due to their adorable appearance and curiosity. They have a distinctive black cap and bib, contrasting with their white cheeks. Their sides are buff colored and the feathers of the wings and the tail are gray with paler edges. They molt every year in late summer, after their breeding season. Visually, it is extremely difficult to identify the sex and age of the chickadees since there are no distinctive features differentiating them. They have an average length of 5 ¼ inches with a wingspan from 6 to 8 inches (5). Black-capped Chickadees use a variety of distinctive calls (fee-bee, chick-a-dee, seet), depending on their intentions (alarms, courtships, etc.) and certain acoustic features in the “fee” part of a call allows us to distinguish between male and female calls (2).

The characteristic black cap and bib make Black-capped Chickadees easy to identify

The characteristic black cap and bib make Black-capped Chickadees easy to identify


The most common place for Black-capped Chickadees to nest is inside cavities of rotten trees dug by them or abandoned by woodpeckers or other birds. When digging their own nest hole, they will scatter the wood chips away from the site to avoid attracting predators. The female is the one in charge of building the nest and uses rabbit fur or soft plant fibers for cushioning (5). She will then lay one egg per day until there are about 6 to 8 eggs. The young hatch after 13 to 14 days and will leave the nest 16 to 17 days after hatching (1).


Black-capped Chickadees are widely distributed throughout North America, being found just below the Arctic all the way to the mid United-States stretching from the Pacific to the Atlantic coast (5). Due to this, the birds make use of many different habitats such as mixed and deciduous woods, thickets, and willow groves. Given suitable nesting areas, they can even be found in urban areas (1). The Black-capped Chickadees are non-migratory birds due their weak flight (5). Despite their weak flight, every few years when there is a large increase in population immature chickadees will fly south for the winter and return north in the fall in a phenomenon known as “irruption”(5).

 Food preference:

Black-capped Chickadees are omnivorous birds whose diet includes insects, berries, and seeds (1). As they do not migrate, the exact content of what they eat varies depending on seasonal availability. Since feeders provide an easy source of food, it is common to see them flock to feeders, but they won’t stay on the feeder long. Chickadees seldom eat on the spot and instead either fly to safety to eat or store their food (called caching) (5). The seeds are stored in various locations to prevent drastic losses if another bird was to find a cache and chickadees have demonstrated an amazing ability to recall these locations (3,5). If the chickadees decide to eat the seeds rather than cache them for later, they often fly away with a seed to a covered branch before holding it with their feet and pecking at it.

video: To eat, Black-capped Chickadees hold the seed with their feet and peck at it with their beak until it breaks open. You can also hear the characteristic “chicka-dee-dee” call they make, where the number of “dees” in the call increases when they feel threatened


Despite their tendency to travel in noisy parties, the friendly Black-capped Chickadee is very choosy about when and with whom it will eat. Upon observing chickadees at a bird feeder, we noticed that they don’t like feeding at the same time as other birds, whether of their own or another species. They patiently wait until one bird has flown away before taking their turn. The weather also influences chickadee’s foraging; on cold, windy days they forage lower to the ground in more dense foliage to block the wind (5).

Video: Chickadees often wait their turn at feeders. It is rare to see two birds, of the same or different species, on the same side of the feeder at the same time. (other bird featured: White-Breasted Nuthatch)

An interesting study done on anti-predator behaviour in Black-capped Chickadees showed that the birds will trade off foraging for safety. After being exposed to a simulated predator, fewer birds visit the food patch and they take longer to come out of hiding to get more food, especially when the patch is further away from their refuge (6). It’s possible to tell when a chickadee is in peril simply by noting the amount of “dees” in their famous “chick-a-dee” call. The more “dees” heard the higher level of threat present (4). It turns out that higher ranked chickadees are leaner than lower ranked individuals, and therefore are more manoeuvrable in the face of predators. That’s not their only advantage; females will select males of higher rank to mate with before considering their subordinates (3). Chickadees become more quiet and inconspicuous during their summer mating season, which is very different from the behaviour we see in the fall (5).


Our Project:

Their non-migratory way of life and stable presence at the Morgan Arboretum makes Black-capped Chickadees the perfect study species for our research. The ease with which they adapt to humans was also key in helping us develop our research question: Does human presence and activity in certain areas of the Morgan Arboretum influence Black-capped Chickadee abundance and behaviour?

With this question guiding us, we used visual and auditory cues to survey six sites in the Morgan Arboretum. The six sites included three sites with lots of human activity off a hiking trail used year round, and the other three were off a snowshoe trail with very little human activity this time of year. Auditory cues were relied on most, and the spacing and direction of calls were used to distinguish if we were hearing one or multiple individuals. If the calls were spaced out and from different directions, they were counted as coming from different individuals, whereas calls that were less spaced and from the same area were counted as one individual. To survey the sites, we split into two groups of two and took different routes in order to obtain more observations of the sites at different times. Once we arrived at a site, we waited five minutes before recording observations so the area was less disturbed. After the five minutes, we recorded abundances as well as behaviours for fifteen minutes. From our three days of data collection we noticed that chickadees do seem to be more abundant in the high human activity sites.


(1) Foote, J.R; Mennill, D.J; Ratcliffe, L.M; Smith, S.M. 2010. Black-capped Chickadee (Poecile atricapillus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; [cited 2015 Oct 27]. Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/039 doi:10.2173/bna.39

(2) Hahn, A.H; Hoang, J; McMillan, N; Campbell, N; Congdon, J; Sturdy, C.B. 2015. Biological salience influences performance and acoustic mechanisms for the discrimination of male and female songs. Animal Behaviour, 104, 213-228.

(3) Otter, K.A. 2007. Ecology and Behaviour of Chickadees and Titmice: an integrated approach. New York: Oxford University Press.

(4) Schwarz, J; Greene, E; Davis, K. 2005. Chickadees’ alarm-calls carry information about size, threat of predator. University of Washington.

(5) Smith, S.M. 1997. Wild bird guides: Black-capped Chickadee. 1st edn. Hong-Kong: Stackpole Books.

(6) Turney, S; Godin, J.G.J. 2014. To forage or hide? Threat-sensitive foraging behaviour in wild, non-reproductive passerine birds. Current Zoology, 60, 719-728.


Spider Diversity at the Morgan Arboretum

Follow us on Twitter: @SpidersMcgill

Natural History of Spiders

Arachnida is an extensive class of arthropods recognized mainly by their eight legs, lack of antennae and carnivorous lifestyle, according to the Encyclopaedia Britannica Online (2015). This class encompasses scorpions, mites, daddy long legs and spiders. Spiders belong to the order Araneae, which includes over 114 families and over 45,732 species reported today (World Spider Catalog, 2015). Spiders, though small, play important ecological roles in the ecosystems in which they reside. Their presence, or lack thereof, can be a critical determinant in insect population and consequently impact plant and animal life alike.

Funnel-web spider at night

Funnel-web spider at night

True spiders have opposite fangs that cross when closed and include all the familiar spiders, except tarantulas which have parallel fangs (Foelix, 2011). Additionally, true spiders are all capable of producing silk within abdominal glands and extract it using a pair of agile spinnerets (Turnbull, 1973). They all use their silk to some degree, whether it be to enclose their eggs within a silk cocoon, create a web or nest, or capture prey.

Anatomy of a "True Spider"

Anatomy of a “True Spider”

Common spider families in Saint-Lawrence Lowlands

The Morgan Arboretum, situated in the town of Sainte-Anne-de-Bellevue, is made up of both forest and grasslands. Within a small spatial range of this reserve, spider diversity can be quite extensive. Below, we profile several families common to the Saint-Lawrence lowlands, which can be observed in the Arboretum. Most of these spiders thrive in the spring and summer months, but many persist into fall.

Family Araneidae – Orb weavers

Compared to other spiders that spin flat orb webs, Araneidae is the family with the most species (Bradley, 2012). Orb weavers include 3,096 species overall (World Spider Catalog, 2015), of which 31 can be found in Quebec (Dupérré, Paquin, 2003). These spiders can be found almost anywhere: cellars, mines, grasses, or forests (Dondale, 2003).  Most are large and colorful, and have round bodies (Bradley, 2012). Orb weavers normally have three claws on each leg, the third claw is short and untoothed which allows the spider to hold on to its webs (Dondale, 2003). These spiders sense prey with web vibrations. As soon as the prey gets caught in the web the spider wraps the prey in a silk cocoon (Bradley, 2012). Their web-weaving includes four main parts: first, the spiders build the basic structure in a physical limit, after that they attach the center of the web to its outside limits using lines of silk, next they make  the temporary spiral, and finally, they replace the spiral with a sticky version, to capture prey (Dondale, 2003).

Female Argiope Trifasciata (Araneidae) resting in her web

Female Argiope Trifasciata (Araneidae) resting in her web

Family Thomisidae – Crab spiders

This family is made up of 2,155 species (World Spider Catalog, 2015), 32 of which can be found in Québec (Dupérré, Paquin, 2003). Their name is due to their crablike posture and movement. The abdomen is “saclike” and is softer than the carapace and sternum found on the cephalothorax (Dondale and Redner, 1978). The dorsal side may have a uniform color, or two lines of a different color, like in Misumena vatia (below). Their colors can be very bright, because crab spiders often capture pollinators. Some may even change color according to the surface they are on (Dondale and Redner, 1978).

Misumena vatia

Misumena vatia

Family Salticidae – Jumping spiders

This family is the largest with 5,841 named species (World Spider Catalog, 2015), 43 of which are found in Quebec (Hutchinson, 2003). They are easily recognizable by the horizontal alignment of four forward-facing eyes and huge distinctive median eyes (Bradley, 2012). These spiders are known for exhibiting intelligent behavior, including elaborate learned behaviors used for hunting their prey (Bradley, 2003). Most jumping spiders are active during the day, possess color vision, and are colorful. Many of these spiders are known for complex courtship rituals that involve movement and their colorful bodies (Bradley, 2012).

Jumping spider (Salticidae)

Jumping spider (Salticidae)

Family Lycosidae – Wolf spiders

Wolf spiders are one of the most widespread spider families, with 53 identified in Quebec (Hutchinson, 2003) and approximately 2,403 worldwide (World Spider Catalog, 2015). They are found in all habitats. The unusual arrangement of their eight eyes in what looks like three consecutive rows makes them easily recognizable and possess excellent vision (Bradley, 2012). Their good eyesight is employed during their mating rituals (Bradley, 2012). Depending on the species, wolf spiders can be active during the day or at dawn and dusk (Bradley, 2012). As they forage, they make use of a dragline, which is the laying down of a silk line that can serve as communication means between different individuals of the species (Bradley, 2012). Most of these spiders are ground hunters, building burrows, and waiting for prey instead of chasing it down (Bradley, 2012).

Our research

Our research is aimed at answering the following question: How does spider diversity differ in the vertical stratification of grasslands along the forest edge of a mixed deciduous forest at the Morgan Arboretum?

Spider collection can be done in multiple ways (Turnbull, 1978). This experiment uses both pitfall traps and sweep nets. Our pitfall traps produced little data in contrast to the sweeping, which may be due to heavy rain showers during the time the traps were set, or to soil settling down around the traps, creating an elevated ledge out of the cup lip, onto which spiders would not climb.

Sweep net method:

Each pitfall trap was filled with antifreeze diluted with water to prevent the liquid from freezing if the temperature reached below zero

Each pitfall trap was filled with antifreeze diluted with water to prevent the liquid from freezing if the temperature reached below zero

The experiment lasted 3 weeks. On October 5th, we located our site and swept the grassland. On October 13th, 45 pitfall traps were set. On October 19th the pitfall traps were collected and a second sweep took place. Sweeping three weeks apart in the rapidly changing temperature of autumn in Quebec resulted in a decrease of the number of spiders collected during the second sweep.


As we started analyzing our samples in the lab with microscopes, we realized that the identification of spider families and species is quite challenging. There are numerous species to choose from, and some identifications even require internal organ analysis which we cannot perform. To help this situation we grouped spiders into over 30 types (morphospecies) based on their appearances and differentiable characteristics.

Many different species collected during this study

Many different species collected during this study

Overall, 119 spiders were classified from the first sweeping, 81 from the second sweeping and 25 from the traps. Additionally, nine spiders were unidentifiable due to severed body segments caused by decomposition within the antifreeze solution.

 Works Cited

Bradley, Richard A. “FAMILY LYCOSIDAE • Wolf Spiders.” Common Spiders of North America. : University of California Press, 2013-05-23.California Scholarship Online. Web. 28 Oct. 2015 http://california.universitypressscholarship.com/view/10.1525/california/9780520274884.001.0001/upso-9780520274884-chapter-35

Bradley, Richard A. “FAMILY SALTICIDAE • Jumping Spiders.” Common Spiders of North America. : University of California Press, 2013-05-23. California Scholarship Online. Web. 28 Oct. 2015.http://california.universitypressscholarship.com/view/10.1525/california/9780520274884.001.0001/upso-9780520274884-chapter-52.

Buddle, C. M., et al. (2006). “Arthropod responses to harvesting and wildfire: Implications for emulation of natural disturbance in forest management.” Biological Conservation 128(3): 346-357. Web. http://www.cfs.nrcan.gc.ca/bookstore_pdfs/25952cannotpostonline.pdf

Dondale, C. D., “Orb-Weaving Spiders of Canada and Alaska”. Ottawa, ON, CAN: NRC Research Press, 2003. ProQuest ebrary. Web. 28 October 2015.

Dondale, Charles D, and James H. Redner. “The Crab Spiders of Canada and Alaska: Araneae: Philodromidae and Thomisidae”, 1978. 200p. Print.

Foelix R. F, Biology of spiders, third edition, New York: Oxford University Press, 2011,419 p, Print,

Hutchinson, Raymond. “L’étude des araignées (Araneae) au Québec–le point et perspectives.” Le Naturaliste canadien 127.1 (2003): 24-31.Web. 27 October 1015. http://wsc.nmbe.ch/statistics/

Paquin P and Dupérré N, Association des entomologistes amateurs du Québec, Guide d’identification des araignées (Araneae) du Québec, Fabreries. Supplement 11. 2003. 259 p. Print.

Turnbull AL. “Ecology of the true spiders (Araneomorphae)”. Annual review of entomology, Volume 18. 1973.

“Arachnid”. Encyclopaedia Britannica. Encyclopaedia Britannica online. Encyclopedia Britannica Inc., 2015. Web. 27 oct. 2015.

“Currently Valid Spider Genera and Species (2015-10-29)”. World Spider Catalog, by World Spider Catalog Association. Last update 2015-10-29. 20 Oct 2015. Web. http://wsc.nmbe.ch/statistics/

“True Spiders (Suborder Araneomorphae)”. iNaturalist. July 08, 2015. Web. 28 Oct. 2015. http://canada.inaturalist.org/taxa/120474-Araneomorphae


Wild Ginger Within the Morgan Arboretum

Wild ginger is an understory perennial that grows up to 6 inches tall at maturity. It springs from an underground network of rhizomes and forms dark green, heart-shaped leaves about 3 inches in diameter. The clonal growth forms a mat of wild ginger that covers the ground, which prevents other seedlings from growing within the colony by effectively out-competing them for light. Allelochemicals found in the plant could also play an important role in structuring the surrounding community (Weston & Mathesius, 2013).

Wild Ginger colony

Wild Ginger colony

Wild ginger evolved in shady, rich, deciduous forests in large colony formations. Flowers are not produced until there are enough resources stored in the underground rhizome. Its flowers, found at the base of its stem, mostly self-pollinate, but a small portion are cross-pollinated by tiny flies. Seed dispersal is mostly done by ants and therefore is short-distance (Cain & Daman, 1997). Nonetheless, clonal growth is the most efficient way for reproduction in wild ginger (Muir, 1995). Like most woodland perennial herbaceous plants, wild ginger is susceptible to habitat destruction since they rely heavily on vegetative reproduction.

Maple forest stand

Maple forest stand

Native Americans and early Euro-Americans used the wild ginger for its flavor which resembles that of the asian plant commonly known as ginger (Zingiber officinale) and for its few medicinal properties. It can be cooked like the common Asian ginger and even has similar medicinal properties. The rhizome can be dried and ground into a powder to be used as a spice. It is often added to soups or can be made into candy. Research was conducted to investigate the legitimacy of wild gingers traditional use as a medicinal plant. It was found that the plant does have antibiotic properties, however the chemicals that give it these properties can be toxic in high doses. Wild ginger remains safe to eat in moderate amounts and can potentially alleviate problems such as stomach aches, hearing loss, convulsions, leg pain (sciatica) and coughing. Although it can be safe to consume as well as beneficial to your health, it is recommended that people still take caution. When eaten raw, the rhizome can induce vomiting so it is also essential to properly prepare it.

Wild ginger typically grows in the deciduous forests of eastern North America ranging from Manitoba to New Brunswick and extending south to Kansas and Florida (Anderson, 2000). It prefers well drained, moist and sandy or clay soils, full-shade to semi-shade and a soil pH between 6 and 7 (Lady Bird Johnson Wildflower Center, 2015). The Asarum canadense is a very common understory plant in Quebec and usually found in bitternut hickory or in linden-maple stands (Leboeuf, 2006). The growing conditions of the plants, especially the soil type, were considered to frame our research question on the natural history of the wild ginger in the Morgan Arboretum, which is:

In the Morgan Arboretum, what are the effects of the different habitats of Asarum canadense on the size of the colonies and the vegetation surrounding them?

The objective of this study is to examine whether there are differences in the colony size within the common habitat range of wild ginger. Based on previous research and literature, we hypothesize that colony size will be larger under forest stands that have well-drained soil and more sunlight.

The Morgan Arboretum is owned and managed by McGill University and is located at the western tip of the island of Montreal. Understory plants in this climate experience a severe cold winter and humid warm summer. Perennial herbaceous plants such as A. canadense have above-ground parts that wither and die in late fall and sprout back from rhizomes when the ground thaws in the spring. The arboretum is divided into different forest stands comprised of both native and non native species. There are many invasive species in the area such as Rhamnus sp., Allaria petiolata, and Euonymus sp., which can pose a threat to native habitats.

Map of Morgan Arboretum. The green points mark the locations of surveyed wild ginger colonies.

Map of Morgan Arboretum. The green points mark the locations of surveyed wild ginger colonies.

Three study areas were selected based on the forest stands that are considered common habitats of A. canadense. These include sugar maple, mixed sugar maple, and Am. beech stands. Sugar maple and mixed sugar maple stands grow on St. Bernard soils, which are nutrient rich and well-drained, while beech stands grown on St. Rosalie soils which also contain high levels of nutrients but are imperfectly drained. The study areas were surveyed at first for the presence of A. canadense colonies. The size of these colonies was then measured and surrounding vegetation within a one meter radius was noted. Colony size is determined by average diameter and number of ramets (individuals). The reason for diameter measurement is based on the observation during surveying stage that the plant clonal growth is almost circular. This growth form is applied to all colony samples except for large colonies that have been restricted by large obstacle (big trees and rocks). To measure the diameter, a random cross section is made across the colony and an average measurement is recorded. Ramets were counted individually within the colonies. Surrounding vegetation within 1 m from the edge of the colony was recorded but frequency data was not collected since the purpose is only to observe which species are capable of growing in proximity to the wild ginger colonies (species richness, not abundance). Proportion of open habitat (shade intolerant) vegetation will be calculated and used as a proxy to indicate the degree of shade tolerance of A. canadense.

This study will provide a record of information regarding soil type and plant species richness surrounding A. canadense colonies which can aid further detailed studies of population and community dynamics at a local and regional scale. Invasive species  are a great threat to biodiversity in Quebec’s woodlands. An existing study was done to observe the interaction of local and invasive flora, in this case between A. canadense and Euonymus fortunei (Smith & Reynolds, 2012). This study suggests that there is a potential for using native plants, such as wild ginger, to manage invasive species. Overall, understanding the habitat and community structure of wild ginger will aid in the management and protection of not only the plant but of other plants and organisms that share its habitat.


Anderson, M. Kat. (2006, May 30) Canadian Wildginger Asarum canadense L.. Retrieved October 27, 2015, from http://plants.usda.gov/plantguide/pdf/cs_asca.pdf

Cain, M., & Damman, H. (1997). Clonal Growth and Ramet Performance in the Woodland Herb, Asarum canadense. The Journal of Ecology, 883-883. Retrieved September 29, 2015, from http://www.jstor.org.proxy3.library.mcgill.ca/stable/2960609?seq=13#page_scan_tab_contents

John Hayden, W. (2010). 2010 Wildflower of the Year. Retrieved October 29, 2015, from http://vnps.org/wildflowers-of-the-year/2010-wild-ginger-asarum-canadense/

Lady Bird Johnson Wildflower Center. (2014, August 6) Asarum canadense. Retrieved October 26, 2015, from http://www.wildflower.org/plants/result.php?id_plant=ASCA

Lebœuf, Michel. Arbres et plantes forestières du Québec et des Maritimes. Waterloo (QC) : Éditions Michel Quintin, 2006.

Muir, A. (1995). The cost of reproduction to the clonal herb Asarum canadense (wild ginger). Can. J. Bot. Canadian Journal of Botany, 1683-1686. Retrieved October 29, 2015, from http://www.nrcresearchpress.com.proxy3.library.mcgill.ca/doi/pdf/10.1139/b95-182

Stritch, Larry. Wild Ginger (Asarum canadense L.). Retrieved October 27, 2015, from             http://fs.fed.us/wildflowers/plant-of-the-week/asarum_canadense.shtml

Kopyt’ko, Ya. F, Shchurevich, N. N., Sokol’skaya, T. A., Markaryan, A. A. and Dargaeva,T. D. Uses, Chemical Composition, and Standardization of Plant Raw Material and Medicinal Substances from Plants of the Genus Asarum L. Pharmaceutical Chemistry Journal, Vol. 47, No. 3, June, 2013 (Russian Original Vol. 47, No. 3, March, 2013 ), from http://link.springer.com/article/10.1007/s11094-013-0917-2

KORZYBSKI, TADEUSZ, KOWSZYK-GINDIFER, ZUZANNA and  KURYŁOWICZ, WŁODZIMIERZ. Antibiotic, origin, nature and properties. 1967, pages 1505-1506, from http://www.sciencedirect.com/science/article/pii/B978148319801950249X

Smith, L., & Reynolds, H. (2012). Positive plant-soil feedback may drive dominance of a woodland invader, Euonymus fortunei. Plant Ecology, 853-860. Retrieved September 29, 2015, from            http://download.springer.com/static/pdf/419/art%3A10.1007%2Fs11258-012-0047-z.pdf?originUrl=http://link.springer.com/article/10.1007/s11258-012-0047-z&token2=exp=1443346944~acl=/static/pdf/419/art%253A10.1007%252Fs11258-012-004

Weston, L., & Mathesius, U. (2013). Flavonoids: Their Structure, Biosynthesis and Role in the Rhizosphere, Including Allelopathy. Journal of Chemical Ecology, 283-297. Retrieved September 29, 2015, from http://download.springer.com/static/pdf/733/art%3A10.1007%2Fs10886-013-0248-5.pdf?originUrl=http://link.springer.com/article/10.1007/s10886-013-0248-5&token2=exp=1443348585~acl=/static/pdf/733/art%253A10.1007%252Fs10886-013-024


Fungi and Invertebrates of the Morgan Arboretum


Fungi are incredibly diverse and provide irreplaceable services for the ecosystem and for us. They range from single-celled yeasts to vast networks of hyphae, the filamentous strands that make up fungi (Waggoner and Speer, 1998). Mushrooms are the fruiting bodies of many fungi; they produce and release spores as a method of reproduction. The rest of the fungus is below the surface, secreting enzymes and absorbing nutrients. The majority of fungi are saprophytes, meaning they feed on dead or decaying organic matter (Waggoner and Speer, 1998). Fungi cycle vital nutrients such as nitrogen and phosphorus back into the ecosystem in a form plants can use. Any organism consuming fungi, such as invertebrates, can access these nutrients directly (Waggoner and Speer, 1998).

Researching existing studies and information on the topic of invertebrate diversity in fungi left us with many unanswered questions. It led us to ask the following research question: in the deciduous forests of the St. Lawrence Lowlands, how does invertebrate biodiversity differ on or within different types of fungi and their relative health?

To answer this question; we conducted a comparative study of the diversity of invertebrates associated with different species of fungi and their state of health. We accomplished this by coming up with a protocol that could be repeated with as much consistency as possible for every sampled fungi. We used a 30x30cm frame-like quadrant to enclose the fungi and its immediate surroundings and then counted every individual invertebrate found in the area. We recorded both the different species (diversity) and the amounts of each species (abundance).

One of the major challenges we faced when observing fungal ecosystems in the field is that they are very small. It is challenging to identify organisms when their size is in millimeters. To adjust to this, we brought magnifying glasses and flashlights to our sampling sites as well as small vials where we would store unknown organisms to be identified later on.

It is surprisingly difficult to find research about the animal biodiversity in fungi. “Although there’s a ton of biodiversity information on the Internet now, it’s absolutely chaotic”, says Bisby, Botanist taxonomy database development. Despite their unpleasant odors, the importance of these fungi is not ignored. Their medicinal properties and rumored association with biocontrol attract many curious minds. However, filtering through the thousands of  scientific articles related to fungi is tedious work and everyone’s research is different. In 2009, Drilling and  Dettner examined the ways in which beetles and other arthropods select a fungus to feed on. Their results were sparse and they were unable to determine a link between compounds with specific scents and the selection process (Drilling, K., and Dettner, K., 2009).

Sadly, mushrooms are often given bad reputations. The entire motivation behind Perley Spaulding’s research on the relationship between insects and fungi was to further understand how “dangerous fungi” were affecting our insect population. He described fungi as “trouble” and said that insects that choose fungi as hosts are “soon DOOMED” (Spaulding, P., 1903).

@MacFungiHunters, an earlier St.-Lawrence Ecosystems Fungi group, asked a question very similar to ours. Without even knowing it, both our first Twitter posts to promote our research were essentially the same joke!


Up until we began our field research, we weren’t sure which fungal species we were going to be studying. During our field labs, we found the following fungi in the most abundance and decided to choose them as our study species; Turkey Tail, Purple Polypore, Artist’s Conk, and Lion’s Mane Coral Fungi. All four fungi fall under the phylum Basidiomycetes.

Below are some pictures taken in the field:


Phylum Basidiomycetes (wood-inhabiting fungi) digest wood by decomposing the lignified cell walls of trees (Blanchette, 1991). Lignin gives trees and other woody plants their tough outer bark and extremely rigid structure and is difficult to degenerate. These fungi are among the oldest organisms on Earth and because they degrade lignin, they are one of the most successful decomposers. This phylum’s distribution and diversity depends on the species of tree and their relative sizes, as well as various environmental factors such as; humidity levels, temperature, sunlight exposure (they do not photosynthesize), and distance to soil contact (Jang, Jang, et al., 2015).

Within Basidiomycetes, are two orders containing our fungal study species; Polyporales (Turkey Tail, Purple Polypore, and Artists Conk) and Russulales (Lion’s Mane Coral Fungus). Polyporales is a very diverse group of fungi and are crucial to the cycling of carbon.  Their white-rot members (best wood decomposers) are the most efficient decayers of lignin in the biosphere, making them ecologically important.

The order Russulales fungi are important economically; some of its groups have many medicinal properties which are widely used in human medicine (Zhou and Dai, 2013). This order also holds most of the edible mushrooms that humans have farmed for hundreds of years and that other mammals and invertebrates benefit from as well (Zhou and Dai, 2013).

The context of our research is important because it is done at the Morgan Arboretum after the first frost. As invertebrates are ectothermic, their body temperature (and as a result metabolism and activity) is highly dependent on the temperature of their surrounding environment (Mellanby, 1939). For this reason we expected to find relatively low invertebrate activity but we were surprised to find that invertebrates found within fungi were there not only to feed but to overwinter and/or reproduce.

The most abundant invertebrate found, we believe is Cis Levetti, a small black Ciidae beetle that burrows its way into Turkey Tail fungi. Ciidae are known to be reliant on fungi as both a food source and a habitat. (Majka 2007). Interestingly enough, none were found in the similarly sized, colored, and shaped Purple Polypore fungus. This may be the result of unfavorable chemical and/or morphological traits of this fungal species.


These preliminary observations suggest that regardless of the tree/fungal decomposition stage, many invertebrates reliant on fungi specialize on one or a few fungal species and may therefore only be found on/in such species.

Literature Cited

Binder, M., Justo, A., Riley, R., Salamov, A., Lopez-Giraldez, F., Sjökvist, E., . . . Hibbett, D. S. (2013). Phylogenetic and phylogenomic overview of the Polyporales. Mycologia, 105(6), 1350-1373. DOI:10.3852/13-003. http://www.mycologia.org.proxy3.library.mcgill.ca/content/105/6/1350.full

Blanchette, R. A. (1991). Delignification by Wood-Decay Fungi. Annual Review of Phytopathology, 29, 381-403. DOI:10.1146/annurev.py.29.090191.002121. http://www.annualreviews.org.proxy3.library.mcgill.ca/doi/pdf/10.1146/annurev.py.29.090191.002121

Jang Yeongseon, Y., Jang, S., Min, M., Hong, J.-H., & Lee, H. (2015). Comparison of the Diversity of Basidiomycetes from Dead Wood of the Manchurian fir (Abies holophylla) as Evaluated by Fruiting Body Collection, Mycelial Isolation, and 454 Sequencing. Microbial Ecology, 70(3), 634-645. DOI: 10.1007/s00248-015-0616-5 .http://download.springer.com/static/pdf/717/art%253A10.1007%252Fs00248-015-0616-5.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs00248-015-0616-5&token2=exp=1446395040~acl=%2Fstatic%2Fpdf%2F717%2Fart%25253A10.1007%25252Fs00248-015-0616-5.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs00248-015-0616-5*~hmac=cc10ffce6c7d5ee4f440512f0c77beea09a552622cd7c0e4e89d59c819c6b7f7

Drilling, K.., & Dettner, K. (2009). Electrophysiological Responses of Four Fungivorous Coleoptera to Volat. Iles of Trametes Versicolor: Implications for Host Selection. Springer, 19(2),109-115.  DOI: 10.1007/s00049-009-0015-9. http://download.springer.com/static/pdf/471/art%253A10.1007%252Fs00049-009-0015-9.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs00049-009-0015-9&token2=exp=1446394612~acl=%2Fstatic%2Fpdf%2F471%2Fart%25253A10.1007%25252Fs00049-009-0015-9.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs00049-009-0015-9*~hmac=d1f276648bb0626c551e96a8400dc6b2b9b20b83be491ab0d8293852d7598ae1

Majka, C. G. (2007). The Ciidae (Coleoptera: Tenebrionoidea) of the Maritime Provinces of Canada: new records, distribution, zoogeography, and observations on beetle-fungi relationships in saproxylic environments. Zootaxa, 1654, 1-20.  Retrieved from http://www.chebucto.ns.ca/Environment/NHR/PDF/Majka_Ciidae.pdf

Mellanby, K. (1939). Low Temperature and Insect Activity. Proceedings of the Royal Society of London. Series B, Biological Sciences, 127(849), 473-487.  Retrieved from http://www.jstor.org/stable/82230

Norris, S. (2000) A Year for Biodiversity: International Biodiversity Observation Year Participants Will Unite to Advance Biodiversity Science and Raise Its Profile Among Policymakers and the Public. BioScience 50(2), 103–107. DOI: 10.1641/0006-3568(2000)050[0103:AYFB]2.3.CO;2 http://bioscience.oxfordjournals.org/content/50/2/103.full.pdf+html

Spaulding, P.(1903) The Relations of Insects to Fungi. The Plant World, 6(8), 182–184. URL: http://www.forgottenbooks.com/readbook_text/The_Plant_World_v6_1000048474/243

Waggoner, B., & Speer, B. (August 8th 1998). Introduction to the Fungi of athlete’s foot, champignons, and beer.  Web. Retrieved from http://www.ucmp.berkeley.edu/fungi/fungi.html

Zhou, L. W., & Dai, Y. C. (2013). Taxonomy and phylogeny of wood-inhabiting hydnoid species in Russulales: two new genera, three new species and two new combinations. Mycologia, 105(3), 636-649. DOI:10.3852/12-011 http://www.mycologia.org/content/early/2013/01/29/12-011.full.pdf+html


Bryophytes of the Morgan Arboretum


Moss, lichen, liverwort; we see these tiny plants every day, but do we ever stop to really think about them? For our natural history research project, we decided to learn more about these plants, also referred to as bryophytes. It was this curiosity that lead to our research question, which is: In what forest types will bryophytes grow the most abundantly in the Morgan Arboretum?

One of the types of mosses we see when strolling through the Morgan Arboretum.

One of the types of mosses we see when strolling through the Morgan Arboretum.

What are Bryophytes?

It is important to first understand what a bryophyte is, and how to identify them. Bryophytes are a major classification of land plants that do not possess a true vascular system or root system. They range in size and are typically green due to chlorophyll, the green pigment found in chloroplasts. This makes them photoautotrophic, so they make their own energy from water, carbon dioxide and sunlight through photosynthesis (Lepp, 2008).

Bryophytes include three phylum (a classification of organisms): Moss (Phylum Bryophyta), Liverworts (Phylum Marchantiophyta) and Hornworts (Phylum Anthocerotophyta) (Crandall-Stotler, 2005). These three phyla have the same life cycle; the only difference is observed in the organization of their leaves. Moss have tiny stems on which leaves are arranged in spirals, whereas liverworts have leafy shoots or flattened thalli (vegetative parts) where the leaves are arranged around two lateral ranks (Crandall-Stotler, 2005). Hornworts look like liverworts, but have a different metabolism. Liverworts synthesize oils and store them as oil bodies which make them have a spicy aroma, whereas hornworts require ammonium for their metabolism and secrete carbohydrate for cyanobacteria (Crandall-Stotler, 2005).

A lichen (left) and a liverwort (right)

A lichen (left) and a liverwort (right)

The reproduction of bryophytes has been researched heavily to better understand the role bryophytes play in the environment. A study in 1979 was conducted, by Heinjo During, to examine the history traits and life strategies of bryophytes. It was found that bryophytes can reproduce asexually and sexually, depending on the species. Asexual reproduction can occur many ways, one being simple fragmentation. This occurs if a piece of the bryophyte breaks off and is transported to a new suitable environment, where it can grow into a new plant. Sexual reproduction happens through the dispersal of spores, which are formed when the male gamete (sperm) is carried to the female gamete (egg) by water, and fertilization occurs. Once this happens, the newly formed spore can be carried (usually by wind) to new surfaces and begin to grow (Lepp, 2008).

Close-up view of some spores

Close-up view of some spores

The history traits of bryophytes also reveal that many species may have co-evolved with other organisms to better adapt to their environment. An example of this is the mutualistic interaction some bryophytes have with fungi shown in the 2014 paper “Forestry impacts on the hidden fungal biodiversity associated with bryophytes”, where the amount of fungal biodiversity varied with the species and relative amount of bryophytes present.

Bryophytes are also key pioneer species meaning they are some of the first organisms to colonize previously disrupted or damaged ecosystems. This was demonstrated in a 1982 experiment by Diana Duncan following the growth of bryophytes after a forest fire, which found bryophyte spores were particularly well suited for germination on burnt soils.

It is commonly thought that bryophytes can only be found in moist environments, but that is not always the case. They are found in nearly every habitat including the arctic and the desert, with the only exception being in the ocean. They can also grow on all kinds of surfaces like rocks, tree trunks, bones, and even discarded shoes (Lepp, 2008). Bryophytes also grow more abundantly in areas with little pollution, so they can be an indicator of a healthier environment (Lepp, 2008).

Soft carpet-like moss

Soft carpet-like moss

Bryophytes also play an important ecological role. “They provide seed beds for the larger plants of the community, they capture and recycle nutrients that are washed with rainwater and they bind the soil to keep it from eroding” (Crandall-Stotler, 2005).

The abundance of bryophytes is dependent on many factors. Research in 2006 by Andersson and Hytteborn measured bryophyte occurrence and the relative amount of decaying wood in natural verses managed forests. They showed that natural forests had more decaying wood in more stages than managed forests which allowed for greater bryophyte richness in natural forests. This is important for our experiment because the Morgan Arboretum is partially managed and is a factor that might affect our data.

Our research

We were able to spend three lab sessions looking at bryophytes in the Morgan Arboretum, a 245-hectare reserve in the western tip of Montreal, and mere minutes from our classroom on the McGill University’s Macdonald Campus.

In order to answer our research question, we looked at the amount of moss, lichen, and other bryophytes in three distinct forest types dominated by a specific species of tree: Beech, Sugar Maple, and Hemlock. This gave us a diverse range of habitats while still being manageable for four undergrads with heavy backpacks in cold October.

To record and measure each forest uniformly, we measured out ten plots, each five by five meters. Each plot was chosen somewhat arbitrarily; we mapped out each forest type along a trail and made our plots about 30 meters apart along the trail and 10 meters into the woods from the trail.

Our experimental method!

Our materials consisted of a tape measure, a clipboard, and a camera; we used our bags to mark the corners of each plot. Once we had an area plotted out, we looked at the trunks and roots of trees, rocks, soil, and dead or decaying matter for any moss, lichen or liverworts. We created a scale to measure of the amount of bryophytes, ranking the percentage of biomass coverage from 0-5, 0 being nothing and 5 being 80-100% coverage. This allowed us to compare each forest type, and each habitat of moss within each forest. We also noted any overall trends in each area, such as the lack of lichen on Beech trunks and the numerous moss covered rocks in Maple-dominated forests.


Andersson, L. I. and Hytteborn, H. (1991), Bryophytes and decaying wood– a comparison between managed and natural forest. Ecography, 14: 121–130. doi: 10.1111/j.1600-0587.1991.tb00642.x

Birse, EM; Landsberg, SY & Gimingham, CH. (1957). The Effects of Burial by Sand on Dune Mosses. Transactions of the British Bryological Society, 3, 285-301.

Crandall-Stotler, B (2005). What are bryophytes? Department of Plant Biology, Southern Illinois University, Carbondale, IL 62901-6509. Retrieved from http://bryophytes.plant.siu.edu/ bryojustified.html

Davey, M., Kauserud, H., & Ohlson, M. (2014). Forestry impacts on the hidden fungal biodiversity associated with bryophytes. FEMS Microbiol Ecol FEMS Microbiology Ecology, 90(1), 313-325. doi:10.1111/1574-6941.12386

Duncan, D., & Dalton, P. (1982). Recolonisation by bryophytes following fire. Journal of Bryology, 12(1), 53-63. doi:10.1179/jbr.1982.12.1.53

During, H. J.. (1979). Life Strategies of Bryophytes: A Preliminary Review. Lindbergia, 5(1), 2–18. Retrieved from http://www.jstor.org/stable/20149317

Lepp, H. (2008, April 15). What is a Bryophyte? Retrieved October 26, 2015.


Variation in the abundance of the red-backed “soil-amander”-Amphibians of the Morgan Arboretum


Nature is full of environmental and biological interactions. Some well-known, like how temperature and precipitation determine vegetation in different environments. Others are less obvious, and require keen observation to see. Last month, in the Morgan Arboretum, we looked at one of these subtle changes: how changing soil types affect the presence and abundance of amphibians. Today, we will focus on the Eastern red-backed salamander (Plethodon cinereus). To know how the environment affects the species, we first need to know a little about it!

Three small red-backed salamanders from the Morgan Arboretum.

Three small red-backed salamanders from the Morgan Arboretum.

Red-backed salamanders are one of the most common species found in most deciduous forests of Eastern North America. They are so common that in some systems their biomass is said to reach 93.5% of the total biomass (Burton and Likens, 1975). This species is small and slender, and has two color morphs- a more common copper-backed “red-back” one, and the “lead-back” (Gibbs, 2007).

A “lead” back and “red” back salamander, side-by-side.

A “lead” back and “red” back salamander, side-by-side.

Like other amphibians, they lay non-amniotic eggs, which are permeable and require moisture to develop. Unlike most amphibians, though, the red-backed salamander’s larvae fully develop inside the egg, making them terrestrial right after birth (Howard, 2003). Amphibians also have bare, permeable skin, which allows them to breathe and absorb water. Since they need to stay moist, amphibians never stray far from water or humid environments. Amphibians’ skin is susceptible to changes in the environment; changes in salt, pH, pollutants, and other contaminants can lead them to be extirpated, making them a good ecological indicator (Green et al. 2014). Their sensitivity also makes them picky when it comes to choosing habitats. Even the lighting can affect a salamander’s abundance (Wyman, 1988).

Size comparison of a tiny juvenile next to a full grown adult.

Size comparison of a tiny juvenile next to a full grown adult.

By feeding on a variety of soil-dwelling invertebrates, Plethodon cinereus plays a big role in its habitat as a predator (Howard, 2003). They are also an important prey item for bigger vertebrates, which helps move nutrients up the trophic levels and keep the ecosystem functional (Wyman, 1998).

Questions & hypotheses

Each species has different environmental needs. We decided to look at  different soil factors affecting species abundance, and so, our question is: which soil type does each species of amphibian in the Morgan Arboretum favor? Since amphibians need to be in areas of high moisture content, our hypothesis was that more would live in soils with imperfect or poor drainage.


We first selected three different soils in the Morgan Arboretum. Our choices were St. Amable, St. Bernard, and St. Rosalie, because they have different soil orders, parent material, and drainage speed (figure 1; Table 1). To find each soil, we used a soil map and dug holes to double-check our location. Each site (6 total- 2 for each soil type) had a 25x25m quadrant. Walking parallel to each other, we sampled each area for 20 minutes while listening for rustling leaves and checking under rocks and logs.

Figure 1. Soil map of the Morgan Arboretum, courtesy of Jim Fyles, with the estimated location of our six sites

Figure 1. Soil map of the Morgan Arboretum, courtesy of Jim Fyles, with the estimated location of our six sites

Problems faced

As the days got colder, amphibian activity decreased, which reduced the diversity of species we found. It is also possible that disturbances caused by animals or fellow students affected our data.

Team members Zoe and Adam recording the air temperature using a soil thermometer, and taking it very seriously...

Team members Zoe and Adam recording the air temperature using a soil thermometer, and taking it very seriously…


Our prediction was that we would find more amphibians in poorly drained areas. Research also told us that we should find more salamanders in moist soils (Taub, 1961). That’s why we were surprised when we found that, out of 214 red-backed salamanders, 163 came from our driest sites, St. Bernard. With good drainage, St. Bernard never once had a water puddle, even after rainy days. So why was this place teeming with salamanders?

We came up with our own conclusion on the requirements needed for a good salamander habitat:

  • less acidic soil
  • rocks and logs to hide under
  • loose, porous soil texture
  • moist soil with good drainage

Some of these conclusions we got through research. Sugalski and Claussen (1997) state that red-backed salamanders prefer less acidic soils. St. Bernard is by far our least acidic soil, so the salamanders’ preference make sense. We found three times more salamanders in St. Amable (39 individuals) than St. Rosalie (13 individuals), despite St. Amable being more acidic. This means there are other variables in play.

Three red-backed salamanders found in a St. Bernard site.

Three red-backed salamanders found in a St. Bernard site.

Most of the salamanders we found were hiding underneath a rock, log, or branch. This led us to realize that objects on the ground were required for salamanders to thrive. St. Bernard, a glacial till, had many rocks, while the other sites had many decomposing logs. While this is an important requirement for salamander habitats, it did not help us determine why they favored certain soils.

A red-backed salamander returning to his home under a log

Aside from acidity, we believed soil texture and drainage were important factors.  Salamanders burrow themselves in soil, which if impenetrable, will not make a good home. It seems that dry soil is too hard, while wet soil is too sticky. Furthermore, like with worms, poorly drained soil could cause salamanders to drown. St. Rosalie is made of clay, which is known to be compact and have micropores (Hillel 1980).  Our St. Rosalie sites were often flooded, making it very difficult not only for sampling, but for salamanders to live. On the contrary, St. Amable and St. Bernard are made of sand and loam, respectively. These are bigger, loose particles, making them easy to bury in. Since St. Amable’s sand is over clay, it did not always drain well, again potentially affecting salamander abundance.

Table 1 : Difference between the soil types used in our project (Agriculture and Agri-Food Canada, 2013)


With more sites and replication, we could figure out if we are right about our variables, or if something else caused the differences in abundance. More well-drained soils with varying soil textures and pH could tell us if red-backed salamanders like all well-drained soils, or if St-Bernard is unique somehow. Further research can also allow us to explore other questions and observations, like why we almost only found juvenile salamanders as it got colder.


Agriculture and Agri-Food Canada [internet]. 2013. Ottawa, ON : Government of Canada; [Accessed 2015 Oct 24]. Available from: http://www.agr.gc.ca/eng/home/?id=1395690825741

Burton TM, Likens GE. 1975. Salamander populations and biomass in the Hubbard Brook experimental forest, New Hampshire. Copeia. [Accessed 2015 Oct 27]; 1975 (3): 541 – 546.

Available from: http://www.jstor.org/stable/1443655. DOI: 10.2307/1443655.

 DM Green, Weir LA, Casper GS, Lannoo MJ. 2014. North American amphibians : distribution and diversity. Berkeley, CA, USA : University of California Press; [Accessed 2015 Oct 26].

Gibbs, JP. 2007. The Amphibians and Reptiles of New York State Identification, Natural History, and Conservation. Oxford: Oxford UP.

Hillel D. 1980. Fundamentals of Soil Physics. Philadelphia, USA: Academic press; [Accessed 2015 Oct]. Available from: http://www.sciencedirect.com/science/article/pii/B9780080918709500017

Howard C. Plethodon cinereus : Eastern red-backed salamander [internet]. 2003. Ann Arbor, MI, USA : Animal Diversity Web; [Accessed 2015 Oct 29]. Available from: http://animaldiversity.org/accounts/Plethodon_cinereus/

Ontario Nature . 2013. Ontario, Canada: Ontario Nature; [Accessed 2015 Oct 26]. Available from: http://www.ontarionature.org/protect/species/herpetofaunal_atlas.php

Renaldo KA, Murch CW, Riley J, Helleman B, Smith GR, Retting JE. 2011. Substrate preference of eastern red-backed salamanders, Plethodon cinereus: A comparison of deciduous and coniferous substrates. Amphibia-Reptilia [Accessed 2015 Oct 26]; 32(2): 266-269. Available from: http://booksandjournals.brillonline.com/content/journals/10.1163/017353710×550913

Sugalski MT and Claussen DL. 1997. Preference for soil moisture, soil pH, and light intensity by the salamander, Plethodon cinereus. Journal of Herpetology. [Accessed 2015 Oct 25]; 31(2): 245 – 250.Available from: http://www.jstor.org/stable/1565392. doi:10.2307/1565392.

Taub FB. 1961. The distribution of the red-backed Salamander, Plethodon c. cinereus, within the Soil. Ecology. [Accessed 2015 Oct 25]; 42(4): 681 – 898. Available from: http://www.jstor.org/stable/1933498. doi: 10.2307/1933498.

Wyman RL. 1988. Soil acidity and moisture and the distribution of amphibians in five forests of southcentral New York. Copeia.[Accessed 2015 Oct 28]; 1988 (2) : 394 – 399. Available from: http://www.jstor.org/stable/1445879. doi: 10.2307/1445879

Wyman RL. 1998. Experimental assessment of salamanders as predators of detrital food webs: effects on invertebrates, decomposition and the carbon cycle. Biodiversity & Conservation. [Accessed 2015 Oct 29]; 7(5): 641 – 650.Available from: http://link.springer.com/article/10.1023%2FA%3A1008856402258 doi: 10.1023/A:1008856402258


Bark Bugs: Saproxylic Invertebrates in the Morgan Arboretum

Invertebrates are a broad category of animals characterized by the lack of a backbone. Surprisingly and most often unknown is the fact that invertebrates amount to a staggering 95%-99% of all animal species (Encyclopedia of Science, 2002). This assorted group includes insects, spiders, crustaceans, and mollusks, all of which are also ectothermic (cold-blooded). Such a diverse group of organisms calls for an indescribable range of adaptations within varying environments (N.W.F, 2000). For example, the adaptations that allow invertebrates in Canada to survive through the seasonal winters, without producing their own body heat.

Click Beetle Larva, one of the many invertebrates found under bark at the Morgan Arboretum

Click Beetle Larva, one of the many invertebrates found under bark at the Morgan Arboretum

Terrestrial species of invertebrates unequipped for migration often rely on biochemical processes to survive sub-zero temperatures, as they are unable to function due to a lack of resources and slower metabolic rates during the winter. These invertebrates exhibit freeze intolerance, and avoid freezing through a process known as supercooling. (Block,1991) This ability allows invertebrates to withstand ice formation within their tissues, to a certain extent. To avoid a lethal level of solidification, many invertebrates produce a surplus of sugars and proteins within their bodies, and reduce water levels to lower their internal freezing temperatures. (Aarset, 1982) However, this alone is often not enough for the invertebrate to make it through the winter. Additionally, during the fall they must also locate a relatively sheltered area to spend the winter season, underneath the bark of a dead tree for example.

Dead beech logs, a perfect hiding spot for invertebrates to overwinter in!

Dead beech logs, a perfect hiding spot for invertebrates to overwinter in!

Saproxylic invertebrates:  Roles and Biodiversity

Speaking of dead trees, an organism that is dependent on dead wood at one point in their life cycle, or on other organisms that are dependent themselves on dead wood, is called a “saproxylic” organism.(Speigth 1991) For our project, we focussed on saproxylic invertebrates.

Fire coloured beetle larva, the most common species in our samples

Fire coloured beetle larva, the most common species in our samples

Millipedes are another example of common invertebrates living in the bark of dead trees

Millipedes are another example of common invertebrates living in the bark of dead trees

As mentioned before, dead trees offer  a good overwintering refuge for saproxylic invertebrates but they also serve as a their main food source and nesting spot. Others are even parasitic of species that nest in dead logs. (Jonsson et al.2012, p.70-76)

Saproxylic invertebrates are a major player in nutrient cycling. They use the dead wood as food source and therefore, not only do they recycle back nutrients into the surrounding environment, the motile ones even disperse the nutrients throughout the forest! They are also the source of food for vertebrates and they create holes in dead wood that are used by mammals and birds to nest. .(Speight, 1989) They might not be the prettiest of inverts but they are definitely a key factor in forest ecology.

The biodiversity of saproxylic invertebrates is influenced by several factors. Species of invertebrates found will be different based on the tree species, with some differences observed between conifers and deciduous trees. (Ehnström, B., Jonsell, M., & Weslien, J.,1998) The stage of decay of the tree, the coarseness of the log, the part of the dead tree (branch or trunk) observed(Ehnström, B. et al.,1998)  as well as the amount of sunlight the dead log gets (Ehnström, B. et al.,1998 , Lindelöw, Å, Lindhe, A., & Åsenblad, N., 2005) also all have an impact on biodiversity. Dead wood connectivity is another factor. This term used to express how close dead logs are to each other (speaking in terms of distance here, not emotional bonds). This influences the biodiversity of saproxylic invertebrates because there is more chance of finding specific food sources where there is high connectivity. Also, as we observed in lab, a lot of these invertebrates are not very mobile and will therefore prefer patches of dead wood over scattered individual logs. (Schiegg, K.,2000). To summarize, saproxylic invertebrates can be very picky.

Maple (Left) v.s. Beech (Right) bark. They have different living conditions to offer to saproxylic invertebrates.

Maple (Left) v.s. Beech (Right) bark. They have different living conditions to offer to saproxylic invertebrates.

Our project

As far as saproxylic invertebrates are concerned, we thought it would be interesting to see whether there were differences in the communities under the first outer layer of bark on two different tree species. Seeing as we were using the Morgan Arboretum as our study area, it made sense to compare maple and beech communities as there are two distinct areas of both sugar maple and beech forest. This means that there would be a higher number of decaying logs to sample, increasing the accuracy of our results, as well as providing a more homogenous environment less prone to edge effects which might influence the invertebrate communities we sampled.

So, just how did we go about getting the answers to our question? Firstly, we found a relatively homogenous area of forest (either maple or beech) and identified dead logs that had a length of at least 1m since that was our minimal distance needed from the log’s edge before we could choose a sampling area. Each log was given a state of decay ranging from one to five, one being little to no decay, and five being heavily decayed and soft. Once a suitable sampling log was found, the top layer of bark was gently prised open with a crowbar, exposing approximately 1600cm2. Three minutes were then allowed to collect all visible invertebrates into jars for later identification and photographing. The removed bark and invertebrates were then returned as found to the sampled area.

Click to see an example of our sampling technique on a maple log, Oct. 19th 2015

An even number of maple and beech trees were sampled at each weekly session to account for temperature fluctuations over the research period.


Aarset, V., Arne. (1982) Freezing Tolerance in Intertidal Invertebrates, 73(4), 576

Block, W. (1991) To Freeze or Not to Freeze, 5(2), 284-190. DOI: 10.2307/2389266

Ehnström, B., Jonsell, M., & Weslien, J. (1998). Substrate requirements of red-listed saproxylic invertebrates in Sweden. Biodiversity & Conservation, 7(6), 749-764. doi:10.1023/A:1008888319031

“Invertebrates.” UXL Encyclopedia of Science. 2002. Encyclopedia.com. (October 30, 2015)

Jonsson, B., Siitonen, J., & Stokland, J. (2012). Other associations with dead woody material. In Biodiversity in dead wood. New York, New York: Cambridge University Press.

Lindelöw, Å, Lindhe, A., & Åsenblad, N. (2005). Saproxylic Beetles in Standing Dead Wood Density in Relation to Substrate Sun-exposure and Diameter. Biodiversity & Conservation, 14(12), 3033-3053. doi:10.1007/s10531-004-0314-y

National Wildlife Federation. (2000) Invertebrates; Philanthropedia

Schiegg, K. (2000). Effects of dead wood volume and connectivity on saproxylic insect species diversity. ECOSCIENCE, 7(3), 290-298. Retrieved October 28, 2015, from http://www.ecoscience.ulaval.ca/en

Speight, M.C.D. (1989). Saproxylic invertebrates and their conservation. Retrieved from http://www.lsuinsects.org/


Turkey tail fungi: Nature’s recycling enthusiasts

Turkey tail fungi growing on a log in the Morgan Arboretum

Turkey tail fungi growing on a log in the Morgan Arboretum

Turkey tail fungi are found in mixed-wood forests on every continent except Antarctica. Known as Trametes versicolor to natural scientists, these fungi are admired for the colourful concentric ring pattern on the cap (or ‘pileus’) of their fruiting bodies. These fungi are in the order Polyporales meaning they have multiple openings known as pores under the mushroom cap that release spores needed to reproduce (Kuo, 2005). They grow in shelf-like formations on logs and other dead wood and are found primarily in mixed hardwood forests (Ostry et al., 2011; Kuo, 2005).

Turkey tail fungi are characterized by multicolored banding on their fruiting bodies – the visible section protruding from logs – with colours usually ranging from light brown, dark brown, burgundy, orange and gray. They also appear green on occasion when soil algae becomes exposed on the mushroom cap (Zavada et al., 2001).

Turkey tail fungi with soil algae on top in the Morgan Arboretum.

Turkey tail fungi with soil algae on top in the Morgan Arboretum.

The texture of turkey tails is velvety, smooth and relatively flat. The pores located under the cap are abundant and small, and can be difficult to observe with the naked eye.

As one of the most abundant polypore fungi in the St. Lawrence Lowlands, turkey tails play a crucial role in forests by breaking down dead wood, recycling nutrients back into the soil and creating space for new growth (Kout 2009; Tuor et al, 1995). Turkey tails are a type of white rot fungi, meaning they have the specific substances need to break-down the main strengthening substance in wood, lignin. This lignin decomposition is what causes the dead wood turkey tails grow on to become soft, white, and stringy over time (Voda et al, 2003).

These three photos clearly demonstrate the range of morphological features that were found in Turkey Tail mushrooms at the Morgan Arboretum.

These three photos clearly demonstrate the range of morphological features that were found in Turkey Tail mushrooms at the Morgan Arboretum.

Identifying Turkey Tails

The presence of pores is actually the most helpful characteristic for naturalists trying to distinguish turkey tails from other similar looking fungi in the forest such as the multicolour gill polypore, Lenzites betulina and the “false turkey tail”, Stereum ostrea. Multicolour gill polypores have very large, maze-like gills on their underside, whereas the false turkey tails are smooth with no pores. However, both of their top-sides can be extremely similar to that of Turkey tails, although false turkey tails have a tougher surface. The tough outer layer keeps them from drying out or freezing so Turkey Tail mushrooms are durable and can usually be found up until December in the St. Lawrence Lowlands. (Ostry et al.,2011; Trametes versicolor, n.d.).

A multicolour gill polypore, found at the Morgan Arboretum. While the top of cap looks similar to turkey tail fungi, its underside actually has maze-like gills.

A multicolour gill polypore, found at the Morgan Arboretum. While the top of cap looks similar to turkey tail fungi, its underside actually has maze-like gills.

Turkey tails outside of the forest

On top of their considerable ecological and aesthetic value, turkey tail mushrooms also have many exciting industrial and medicinal applications. As a result of this mechanism, the fungus is in use as a more environmentally friendly method of bleaching pulp to make paper (Taveres et al, 2007). Researchers have also found that the turkey tails are capable of decomposing some man-made substances, and studies are being conducted using the fungi for the decomposition of industrial dyes used for textiles, and a variety of wastewater treatments (Borchet & Libra, 2001).

Turkey tails are edible, but not palatable! However, they have been popular throughout history as folk medicine in societies from ancient China to pre-colonial North America. The fruiting body of turkey tail contains a type of complex carbohydrate that modern western medicine has recently taken interest in as a potential early treatment for some types of cancer that can inhibit cancerous cell growth, with promising clinical trials currently being conducted (De Silva et al, 2012).

Our research

Despite their abundance in forests and the considerable research on the use of turkey tails for industry and medicine, there was surprisingly little research on their specific ecology . We knew that the species was more common in mixed hardwood forests, but they do still appear in coniferous and other forest types. When we first visited the Morgan Arboretum, we noticed there was a wide range of morphological characteristics in the turkey tails we came across, and there were some areas where they were extremely common. While we now have more practice identifying fungi and know that some of these were surely false turkey tails, real turkey tails do display very varied traits as you can see in some of our pictures above. We were curious if there was any relationship between the morphology or abundance of turkey tails and different habitats.

A map of the Morgan Arboretum showing the location of different forest types.

A map of the Morgan Arboretum showing the location of different forest types.

With different forest types within walking distance to each other, the 245 hectare Morgan Arboretum was an ideal place to conduct this research, letting us make observations in in hemlock, coniferous and mixed deciduous forest (Morgan Arboretum, 2014).

Video 1: Site selection and data collection for our research!

In order to be able to collect enough data, we intentionally selected areas where there was a distinct presence of dead trees. However, to ensure an unbiased approach to our research, we did not especially look for fungi before defining our specific area of study. We used the randomly selected our data collection sites by tossing a stick and walking 30 steps from the direction it landed in. From here, we defined an area which was 4 meters wide and 15 meters long.

We then started checking the area for turkey tails, and recording our findings. First, we counted the number of turkey tail specimens in four equal size ranges from under 2.5cm to over 10. We also noted the specific primary and secondary colour pattern on the turkey tail caps and counted how many there were of each. Finally, we tallied the overall number of turkey tails in the study area before moving on to a new one, with each ‘shelf’ being counted as one.

While looking for turkey tails, we had to be aware that there are a variety of species that look quite similar, as we mentioned above. We used an identification chart and looked for signature characteristics such as colour, texture, and underside structure.

A useful identification chart for turkey tails (Source: the Distracted Naturalist, 2013)

A useful identification chart for turkey tails (Source: the Distracted Naturalist, 2013)

We are excited to analyze our data that we have collected over the last few weeks and determine if there may be a pattern to all the varied and beautiful turkey tails we have seen!


Borchert, M., & Libra, J. A. (2001). Decolorization of reactive dyes by the white rot fungus Trametes versicolor in sequencing batch reactors. Biotechnology and bioengineering, 75(3), 313-321.

De Silva, D. D., Rapior, S., Fons, F., Bahkali, A. H., & Hyde, K. D. (2012). Medicinal mushrooms in supportive cancer therapies: an approach to anti-cancer effects and putative mechanisms of action. Fungal Diversity, 55(1), 1-35.

The Distracted Naturalist. “Turkey Tails”. thedistractednaturalist.com. Web: Nov. 27, 2013.

Kuo, M. (2005, March). Trametes versicolor: The turkey tail. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/trametes_versicolor.html

Morgan Arboretum. morganarboretum.org.Web: Thurs. October 30, 2014

Ostry, M. E., O’Brien, J. G., & Anderson, N. A. (2011). Field guide to common macrofungi in eastern forests and their ecosystem functions: General Technical Report NRS-7. United States Department of Agriculture: Government Printing Office.

Zavada, M.S., Dimichele, L., & Toth, C.R. (2009) The demi-lichenization of Trametes versicolor Pilat (Polyporaceae): The transfer of fixed CO2 from epiphytic algae to T. Versicolor. Northeastern Naturalist 11:1, 33-40.

Trametes Versicolor. (n.d.). Sierra club Pro. Retrieved from http://www.sierrapotomac.org/W_Needham/TrametesVersicolor_111223.htm

Xavier, R. B., Maria, A., Mora Tavares, A. P., Ferreira, R., & Amado, F. (2007). Trametes versicolor growth and laccase induction with by-products of pulp and paper industry. Electronic Journal of Biotechnology, 10(3), 444-451.


The Abundance of Earthworms with Human Activity


We are McGill university undergrad students studying environmental biology. In the course St. Lawrence Ecosystem (ENVB 222), we will be conducting a research project geared at evaluating earthworm abundance in the Morgan Arboretum. To expand on the data collected by researchers in last year’s class, we chose to further study earthworms, but in relation to their distribution with compaction. This specific aspect was chosen because the Morgan Arboretum has distinct paths and trails used for both recreation and research. We were interested in viewing the impact of human interactions with the earthworm habitat. This lead to the formation of our research question:

How does earthworm abundance in the Morgan Arboretum change in relation to soil compaction taking into consideration the acidity and temperature of the soil, in two different soil series?

What is an earthworm?

Earthworms are hermaphroditic annelids that are composed of repeating segments called metameres, each of which contains the same internal structures. Externally, earthworms are covered in hair-like structures called setae, which attach to the surface they are digging in and aid in locomotion. These invertebrates feed on dead and decaying plant matter and excrete humus, which is the organic component of soil (Edwards C.A.).

Figure 1: Nutrient cycling - the secretion of humus by an earthworm.

Figure 1: Nutrient cycling – the secretion of humus by an earthworm.

When broken down, the present nutrients become more readily available for plants. In addition, earthworms aerate the soil by their burrowing actions, allowing for more air and water infiltration. These actions can be very advantageous for gardens and other small
and controlled environments, but there is a growing concern about how earthworms (especially the invasive species from Europe) are influencing our North American forest ecosystems.

Why are earthworms considered invasive species?

An invasive species is a plant or animal that is not native to a specific location that has a tendency to outcompete a native species and be detrimental to the environment. There are 180 species of earthworms in North America, 60 of which are invasive (Wikipedia). Our research will be conducted in the Morgan Arboretum, which is a 245 hector forested reserve located on McGill university’s MacDonald campus. Like many-forested regions in North America, the Morgan Arboretum has adapted to having a large amount of leaf-litter on the forest floor, which has influenced production by protecting seedlings and insulating the earth and organisms lying underneath. With the addition of invasive earthworms to North American soils, the composition of the earth is threatened.
One worry is that this will increase soil erosion, as there is less to inhibit the flow of water, which would cause more topsoil to be removed, as well as leach away the vital minerals and chemicals required by the local vegetation (Bohlen, P.J.).

Figure 2: Burrowing action of earthworms seen in St. Bernard soil.

Figure 2: Burrowing action of earthworms seen in St. Bernard soil.

Where do you study earthworms?

Our research project took place over three weeks, where we had three laboratories of four hours to collect our data. Based on last year’s researchers, we chose St. Bernard soil series as our primary area of study as it exhibits desirable living conditions for earthworms. We randomly chose another soil series (St-Amable) in order to compare the results. St. Amable is characterized by sandy conditions, so we expected to find fewer earthworms in this soil.

Figure 3: The Morgan Arboretum forest types, overlain with designated areas of study. The red region represents St. Bernard soil, and the blue shows St. Amable soil.

Figure 3: The Morgan Arboretum forest types, overlain with designated areas of study. The red region represents St. Bernard soil, and the blue shows St. Amable soil.

Methods of study

It was important to ensure that our dig sites were representative of the area, so we chose to use random sampling. During the first two laboratories, our research question was misleading so we hadn’t yet developed a regular method of data collection, so we hadn’t yet determined a proper way to measure compaction. Non-the less, we started by using a measuring tape to dig holes 25cm in diameter and 15cm depth. We used a generic garden shovel to dig these holes. We dug holes near the path at first, then at further distances perpendicular from the path. At this point we had not developed a standardized method of sampling so our intervals varied randomly. As our research question became clearer, we refined our methods and dug holes at 0, 1, 3, 5 and 15 meters away from the path. If there were trees or large rocks in our way we would take three steps to the right (parallel to the path) and continue digging. This ensured that the distance from the path had not been changed. We repeated these steps twice in the two different soil series. Our refined methods allowed us to more accurately determine if earthworm abundance changed with soil compaction at the path.

After digging the hole, we would sift through the earth in search of earthworms. It should be noted that for this research, due to time constraints, it was not feasible to identify specific earthworm species and therefore all earthworms were considered.

A penetrometer was used to measure soil compaction. It was important to measure soil compaction before disrupting the area, to ensure that the soil had not yet been altered by our presence. At each dig site, we took 5 readings from the penetrometer to obtain a representative average. If the soils were too wet, the penetrometer would slip into the ground without producing a reading. In such cases, several steps were taken in each direction of the dig site in order to obtain proper compaction readings.

Worm Fig 4
Temperature and acidity readings were also collected for each hole. Knowing that “[earthworm] density, diversity, and survival are typically low in acidic soils” (Moore, J.-D.), we were expecting less worms in lower pH. Our readings were taken halfway down the hole in order to account for discrepancies in temperate and acidity from the soil surface to the base of the hole. Temperature was an important variable to measure because as we continued our research throughout the months of October and November, the ground temperature continued to decrease and it is a fact that low temperatures limit earthworm distribution (Greiner, H. G.).

Figure 5: Various species of earthworms found in St. Bernard soil.

Figure 5: Various species of earthworms found in St. Bernard soil.


Clive A. Edwards and P.J. Bohlen (1996) Biology and Ecology of Earthworms, Volume 3.Champlain & Hall, London, 433 pages.

Great Lakes Worm Watch. (n.d.). Retrieved November 7, 2014, from http://www.nrri.umn.edu/worms/default.htm

Holly G. Greiner, Andrew M. T. Stonehouse, and Scott D. Tiegs (2011) Cold Tolerance among Composting Earthworm Species to Evaluate Invasion Potential. The America Midland Naturalist 166 (2) : 349-357.

Invasive earthworms of North America. (n.d.). Retrieved November 7, 2014, from http://en.wikipedia.org/wiki/Invasive_earthworms_of_North_America

Jean-David Moore, Rock Ouimeta and Patrick J. Bohlenb (2013) Effects of liming on survival and reproduction of two potentially invasive earthworm species in a northern forest Podzol. Soil Biology and Biochemistry 64 : 174-180.

Patrick J Bohlen et al. (2004) Non-native invasive earthworms as agents of change in northern temperate forests. Frontiers in the Ecology and the Environment 2 (8): 427-435.

Salamanders: Their natural history and our research. (2013, November 11). Retrieved November 7, 2014, from https://stlawrencelowlands.wordpress.com/2013/11/25/salamanders-their-natural-history-and-our-research/


Critters in the Litter

Arthropods are a successful group of invertebrate animals; they are members of the phylum Arthropoda, which is known to be the largest phylum in the animal kingdom. The distinguishing feature of Arthropods is the presence of a jointed external skeleton composed of chitin, a nitrogen-containing sugar (Barnes,2014). Furthermore their body is divided into distinct parts, they have jointed legs and appendages and have bilateral symmetry.

Figure 1: A distinct coloured arthropod found in sugar maple leaf litter.

Figure 1: A distinct coloured arthropod found in sugar maple leaf litter.

Arthropods are known to be present in every habitat on earth and therefore show a great variety of adaptations. Some inhabit aquatic environments while others inhabit terrestrials ones (Barnes, 2014). The topic of this project specifically relates to the leaf litter habitat of these arthropods. Leaf litter is dead plant material, which has fallen to the ground. This dead organic matter and its constituent nutrients are added to the top layer of soil.

Arthropods are predated by a wide range of species: birds and bats (Kalka, 2008). Other arthropods such as spiders, mites and centipedes can use leaf litter critters as food. In that sense, arthropods have a diverse nutrition: some directly consume the components of the leaf litter and others predate on other arthropods, and even sometimes on small mammals. Some leaf litter critters can also be parasitic on other organisms, such as the beaver beetle, whose host is the beaver (Peck,2006).

Arthropods contribute to important functions within the forest environment including nutrient cycling, litter decomposition and pollination (Buddle et al., 2006). In this case, arthropods contribute to the consumption of the litter, which result in the breakdown of simple carbon compounds and the release of inorganic ions (Bot, 2005). A succession of arthropod species are involved in the process of breakdown as the leaf litter decomposes (Crossley et al, 1962)

Figure 2: Vials containing arthropods collected during the field work.

Figure 2: Vials containing arthropods collected during the field work.

Our Project

Research question: How does forest type affect the abundance and diversity of leaf-litter arthropods in the Morgan Arboretum?

Initially, we were interested in looking at the composition of the leaf litter in different forests and how it affected arthropod abundance and diversity. This would include determining the soil pH, temperature of the leaf litter, and the amount of sunlight reaching the forest floor. After considering the amount of time it would take to measure these factors in addition to collecting insects, we decided to look at the effect of forest type instead, since that alone should influence the amount and types of insects that we find.

The four areas we studied were coniferous, maple, beech forests, and grassland as a control. As forest type changes leaf litter characteristics change, for example the thickness of leaf litter, pH, temperature, moisture, light penetration, rate of decomposition and many others. For instance, soils of coniferous forests have a lower pH than deciduous forests. These changes can influence arthropods, notably with the availability of nutrients.

Our expected results are dependent on the forest type. Since the coniferous forest has a more acidic soil and a small amount of leaf litter (Berg & McClaugherty, 2003), the abundance of arthropods is expected to be lower than the Maple and Beech forests, although more abundant than the grassland. The acidity of the soil reduces the available nutrients which will affect the amount of species found. The Maple and Beech forests will have a greater thickness to their leaf litter due to the slow rate of decomposition (Berg & McClaugherty, 2003), allowing the arthropods to have a wider and protected habitat space, therefore having a greater abundance of species. Lastly, in the case of the grasslands, since we are focusing only on leaf litter arthropods (not taking into account anything lower than the leaf litter layer), with an absence of leaf litter we expect our result to have very little to no arthropods being found.

Arthropods have to be able to adapt to the availability of nutrients, as a result we expect that arthropods will be divided among the forest types by their food habits. Hence, there will be variation in arthropods from one forest to another.


Our research was conducted in the beautiful Morgan Arboretum, a 245 hectare forested reserve which is situated on McGill University, Macdonald Campus in St-Anne-de-Belleuvue.

Video 1: A view of the research field at the Morgan Arboretum

In order to help answer the research question two separate collection methods were derived. For the first method we set pitfall traps in the forest. The second method involved sifting the leaf the litter. In both cases the same four forest types were examined; Sugar Maple, Beech, Coniferous and finally grasslands as a control.

Figure 3: The four forest types examined as put of the method. Beginning top left and moving clockwise you see coniferous, grassland, sugar maple, beech.

Figure 3: The four forest types examined as put of the method. Beginning top left and moving clockwise you see coniferous, grassland, sugar maple, beech.

The first data collection method, pitfall traps, involved digging a hole in the soil into which a container with small amount of ethylene glycol is placed. The following week the pitfall traps would be examined and the insects within would be collected. The second method involved sifting a 50cmX50cm square of leaf litter and collecting the arthropods that were present.

Figure 4: A pitfall trap placed in the beech forest.

Figure 4: A pitfall trap placed in the beech forest.

figure 5 Arthropods

Figure 5: A 20cmX20cm square of sugar maple leaf litter to be sifted.

Figure 6: Demonstration of the sifting methods.

Figure 6: Demonstration of the sifting methods.

Three pitfall traps were set and three areas were sampled for sifting, in each of the forest types. This same method was repeated twice. As a result these methods will allow the examination of both the diversity and the abundance of the leaf litter arthropods


Barnes, Robert.D. (2014, July 17th). Arthropod. (Retrieved from http://www.britannica.com/EBchecked/topic/36943/arthropod on October 7th 2014)

Berg, B., & McClaugherty, C. (2003). Plant litter. Decomposition, humus formation, carbon sequestration. Berlin, DE.© Springer-Verlag Berlin Heidelberg. (pp. 76-77)

Bot, Alexandra (2005). The Importance of Soil Organic Matter. Rome: Food and Agriculture Organizations of the United Nations. pp. Chapter 3. ISBN 92-5-105366-9

Buddle, C. M., et al. (2006). “Arthropod responses to harvesting and wildfire: Implications for emulation of natural disturbance in forest management.” Biological Conservation 128(3): 346-357. (http://www.cfs.nrcan.gc.ca/bookstore_pdfs/25952cannotpostonline.pdf)

Crossley, D. A., Jr. and M. P. Hoglund (1962). “A Litter-Bag Method for the Study of Microarthropods Inhabiting Leaf Litter.” Ecology 43(3): 571-573. (http://www.jstor.org.proxy1.library.mcgill.ca/stable/1933396?seq=3)

Margareta B. Kalka, Adam R. Smith and Elisabeth K.V. Kalko, Bats Limit Arthropods and Herbivory in a Tropical Forest. Science 4 April 2008 (5872), 71. [DOI:10.1126/science.1153352] (Retrieved from http://www.sciencemag.org/content/320/5872/71.full )

Peck, S. B, Distribution and biology of the ectoparasitic beaver beetle Platypsyllus castoris Ritsema in North America (Coleoptera: Leiodidae: Platypsyllinae). Insecta Mundi March–June 2006, 20 (1–2): 85. ISSN 0749-6737 (Retrieved from http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1054&context=insectamundi)

8.Vanessa L. Fox, Charlotte P. Buehler, Chad M. Byers, Summer E. Drake, Forest composition, leaf litter, and songbird communities in oak- vs. maple-dominated forests in the eastern United States, Forest Ecology and Management 259 (2010) 2426–2432 [DOI:10.1016/j.foreco.2010.03.019]


Squirrel Nests in the Morgan Arboretum

Squirrels are mammals that belong to the Sciuridae family, which is included in order Rodentia (rodent) (Macdonald 2009). They are among the most common and widespread mammals and are found in almost all regions of the world, excluding the arctic, Madagascar and desert areas. These large-eyed, bushy-tailed, diurnal (active during the daytime) animals are relatively unspecialised, instantly recognisable and can often be quite clever (Macdonald 2009). Tree squirrels always descend tree trunks head first, digging their sharp claws into the bark like an anchor (Macdonald 2009).  As they are generally perceived as attractive or “cute” animals, most people do not consider them pests like other rodents. For example, their distinctive way of feeding by squatting on their haunches and holding food in their forepaws can be considered very amusing.

An eastern grey squirrel enjoying some fresh acorns.

An eastern grey squirrel enjoying some fresh acorns.

Popular conceptions have led many to believe that squirrels hibernate. However, most species, including the ones found in the Morgan Arboretum, stay alert during the winter and rely on the nuts they have stored in the autumn (Macdonald 2009). Shockingly, a single squirrel can bury several hundred nuts every year. Individuals can smell nuts buried as deep as thirty centimeters, but many are never found which results in inadvertent tree seed dispersal (Steele & Al. 2006). Instead of hibernating like many other mammals, they must exit their nests to dig up the nuts they have stored in the previous months. Tree squirrels cannot spend more than two days inside their nest without having to exit and forage in the cold (Macdonald 2009).

Eastern grey squirrels (Sciurus carolinensis) and red squirrels (Tamiasciurus hudsonicus) are the two species of rodents found in the Morgan Arboretum of McGill that construct perched tree nests, also known as dreys (McGill Arboretum 2013). Spherical shaped dreys are constructed with small branches, twigs and grass, and are insulated with dry grass, moss and fur (Macdonald 2009). The number of dreys is a good indicator of the abundance of squirrels, but grey and red squirrels have very similar nest building strategies (Don 1985). This makes it nearly impossible to differentiate to which species a drey belongs (Gurnell et al. 2004). Red squirrels tend to prefer coniferous forests since they prefer to feed on pine cones over the fruits of maple, oak and hazel trees that make up the majority of the grey squirrel diet (Riege 1991). These nests allow the squirrels to function at a very low metabolism during most of the winter (Reynolds 2008) and are so well insulated that temperatures inside are usually around twenty degrees celsius higher than the outside temperature (Macdonald 2009).

A squirrel’s drey, or tree nest, built on top of a beech tree in the Morgan Arboretum.

A squirrel’s drey, or tree nest, built on top of a beech tree in the Morgan Arboretum.

Research question:

Is there a relationship between squirrel nest abundance in the Morgan Arboretum and the forest types and tree species they are found in?


To test our research question, we sampled within seven 75×75 meter plots in the Morgan Arboretum. We tried to sample a variety of forest types, such as maple-dominated forest, beech-dominated forest, and coniferous forest. To create our sampling area, first a tree in the type of forest we wanted to test was marked with a piece of flagging tape. Two lines forming a right angle from this tree were then made, using two people walking 75 meters from the tree and marking a tree at the end of their lines with flagging tape. They then each turned 90 degrees towards each other and walked another 75 meters, marking the point they meet with flagging tape to make the final corner of the square. We then recorded the GPS location and forest type of the site.

The research group would then walk around the perimeter of the square, stopping every time a squirrel nest was spotted to record the species of the tree and the diameter of the tree 1.5 meters from the ground. A picture was then taken of the nest, and the tree was marked with flagging tape to avoid counting the same trees more than once. This procedure was repeated until the entire perimeter of the plot had been surveyed. Finally, a diagonal cross section was made through the plot, walking from one corner to its opposite to record any nests that resided in the middle. A final walk through was then done to remove all flagging tape from the area.

A map showing the position of the nests we found in the Arboretum, mainly in mixed deciduous forests, dominated by maple and oak.

A map showing the position of the nests we found in the Arboretum, mainly in mixed deciduous forests, dominated by maple and oak.


Don, B. A.C. (1985). The use of drey counts to estimate Grey squirrel populations. Journal of Zoology, Vol. 206, No. 2, pp.282-286. DOI: 10.1111/j.1469-7998.1985.tb05656.x. Retrieved from: http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1985.tb05656.x/abstract

Gurnell, J., Lurz, P.W.W., Shirley, M.D.F., Cartmel, S., Garson, P.J.,Magris, L. and Steele, J. (2004). Monitoring red squirrels Sciurus vulgaris and grey squirrels Sciurus carolinensis in Britain. Mammal Review, Vol. 34, No. 1-2, pp.51-74. DOI: 10.1046/j.0305-1838.2003.00028.x. Retrieved from: http://onlinelibrary.wiley.com/doi/10.1046/j.0305-1838.2003.00028.x/full

Macdonald, D. (2009). Squirrels. In The encyclopedia of mammals (New ed., p. 151). Oxford: Oxford University Press.

Morgan Arboretum. (2013). Mammals. Nature. Retrieved from: http://www.morganarboretum.org/nature-en/mammals.html

Reynolds, J. C. (1985). Autumn-winter energetics of Holarctic tree squirrels: a review. Mammal Review, 15: 137–150. doi: 10.1111/j.1365-2907.1985.tb00395.x. Retrieved from: http://onlinelibrary.wiley.com/store/10.1111/j.1365-2907.1985.tb00395.x/asset/j.1365-2907.1985.tb00395.x.pdf?v=1&t=i26o09oh&s=a5370763d1325426f65775ddb46a96f87443b03c

Riege, D.A. (1991). Habitat Specialization and Social Factors in Distribution of Red and Gray Squirrels. Journal of Mammalogy, Vol. 72, No. 1, pp.152-162. Article DOI: 10.2307/1381990. Retrieved from: http://www.jstor.org/stable/1381990

Steele, M. A., Manierre, S., Genna, T., Contreras, T. A., Smallwood, T. D. and Pereira M.E. (2006). The innate basis of food-hoarding decisions in grey squirrels: evidence for behavioural adaptations to the oaks. Animal Behavious, Vol. 71, No 1, pp.155-160. DOI: 10.1016/j.anbehav.2005.05.005. Retrieved from http://www.sciencedirect.com/science/article/pii/S0003347205003374


Walnut Trees and Plant Species Diversity

Natural History of The walnut trees

Walnut Fig 1

In North America, some of the most common members of the Juglandaceae family are Juglans cinerea and Juglans nigra, otherwise known as the Butternut or White Walnut and the Black Walnut or American Walnut respectively. These trees are found throughout eastern North America, and prefer deep, moist, fertile soils of bottomlands and gentle slopes, often occurring as an occasion tree amongst a deciduous forest of hardwoods (Juglans nigra (F) ), (Black Walnut: Juglans nigra). They are therefore a good object of study in the arboretum.

J. nigra is one of the most valuable hardwood trees in the United States, and has been used for everything from flooring to gunstocks throughout US and Canadian history. Because of its versatility, the species has become scarce and nearly extinct in some areas. Not native to the St. Lawrence Lowlands, the Black Walnut’s appearance in the Morgan Arboretum is of unknown origin. It is possible that the species was propagated from southern Ontario or the northeastern United States, due to its widespread use as a hardwood (Black Walnut: Juglans nigra).  A deciduous tree, the Black Walnut can be recognized by its pinnate leaves with 15-21 leaflets, as well as its dark, deeply furrowed bark (Juglans nigra (F) ) It can also be is typified by pedicellate (having a pedicel, a stem)   flowers that lack carpels (staminate)  (Stanford, Harden and Parks).

The Black Walnut Fruit

The Butternut tree is native to the St. Lawrence Lowlands and also minor component of deciduous forests in the area (Canada). It can be identified by its unique bark consisting of flat grey ridges arranged in a diamond or “X pattern” (Winter three identification) , as well as its compound leaves consisting of 11-17 leaflets ((Stanford, Harden and Parks). A somewhat fast growing and short lived tree, commonly dying after 75 years, starts producing fruit at about 20 years of age (Canada). These edible nuts are easily recognized by their hard jagged ridged shell covered by a green hairy husk (Stanford, Harden and Parks).

The Butternut Fruit

The Butternut Fruit

Perhaps the most defining characteristic of the Juglans Genus is the secretion of the chemical Juglone-C10H6O3– (Hejl, Einhellig, Rasmussen) into the soil surrounding the tree. Contained in the roots, leaves, fruit, and bark of the tree, this chemical inhibits the growth of many species of plants (Growing Hardwoods). Being that these trees are not shade tolerant, this chemical is Juglans’ way of eliminating competition in a deciduous hardwood forest. In fact, many trees planted beside the black walnut and this decline was attributed to Juglone (Hejl, Einhellig, an Rasmussen). However it should be noted that there are species such as beech, birch, and others that are tolerant to Juglone and are often times the only trees found surrounding a dense population Walnut trees (Appleton & Al.).

The secretion of Juglone is called an “allelopathic” interaction. In other words, the walnut can influence the growth and therefore the diversity of the plants in its surroundings by the mean of a chemical (Growing Hardwoods). Our goal as an undergraduate research team, was to verify if the presence of the walnut trees had a noticeable impact their environment, the Morgan Arboretum.

Our research question and our method

As we could not measure the very release of Juglone, we simply focused on the diversity of plants species found around the walnut trees in the arboretum. Therefore, we asked the following question:

“What is the diversity of plant species in the vicinity of the walnut trees in the Morgan Arboretum?”

We were more interested in the number of species and the broad category in which they fit, rather than the species themselves. The “broad categories” we used:

  •   A fern,
  •   A small plant of the understory or a shoot (less than 1 meter high, not woody),
  •   A shrub or a young tree (woody, more than 1 meter high),
  •   A mature tree (woody, cannot be hold tightly in the hand; e.i. diameter bigger than 10cm)

Mosses and fungi were excluded from the data as most mosses observed grew on rocks. Also, Fungi are not known to be affected by the chemical (Appleton & Al.).

That being said, we sampled thoroughly the number of plant species around the walnut trees:

  •   Step one: Identifying the walnut trees. Because of the time of the year, most leaves were gone on the trees part of the Juglan family. So, they were identified on the basis of two criteria: the bark and the branching. The butternut trees have a light bark with an “X pattern” made of flat, white ridges (Winter three identification). The black walnut has a dark bark with deep furrows. It is dark brown in the inside (Winter three identification). This bark can be confused with the bark of the ash tree. But the ash tree has opposite branching, whereas the walnuts have alternate branching (c.f. pictures and drawing). We also looked for fruits (nuts) below the litter.
  •   Second step: Setting up a distance of sampling. We chose the distance of 7 meters from the bark as it corresponds to the branch cover (the “Drip Line”) and the estimated root radius of most walnut trees in the Morgan Arboretum.
  •   Third Step:  Sampling in circular zone–7 meters in diameter– around the bark of the trees with the use of a measuring tape. The type of plants (described above) was noted and its distance from the tree was recorded as well. We took a picture of every species and labeled them with a number on the picture to be able to recognize them from tree to tree.

Thirteen trees were sampled. A total of six walnut trees were found in different part of the forest (Juglans cinerea trees and three Juglans nigra). Same sampling methods for the same number of “control trees” (oak, maple, and shagbark trees chosen randomly in the same part of the forest than their corresponding walnut) was done. The three black walnuts (Juglans nigra) we sampled were found in a patch of the Arboretum composed almost uniquely of black walnut trees. Since this patch was crowded with black walnuts, we could not sample a control tree in this area and thus sampled one control tree for all three black walnut in an area nearby.

Data sampling with the use of measuring tape

Data sampling with the use of measuring tape

Problems encountered

Two major problems were encountered. Firstly, finding a significant number of butternut trees in the Morgan Arboretum was a challenge. Hence, our research question, initially focused on white walnut, was broadened to walnut trees (black walnuts were more abundant in the Arboretum). Secondly, the time of year caused problems. In fact, between the first and second session of data sampling (one week apart), most of the plants from the understory had wilted because of the cold. It is why on the second lab, we sampled a lot more shrubs and trees than small plants. Also, the walnuts were harder to identify as the leaves had fallen.

Works Cited

Alice M. Stanford, Rachel Harden, and Clifford R. Parks. “Phylogeny and  Biogeography of  Juglans” American Journal of Botany 87(6): 872–882.  June 2000. University of North Carolina, Chapel Hill, North Carolina 27599 USA. American Journal of Botany Online. Web 04 November. 2014.

Angela M. Hejl, Frank A.  Einhellig, and James A. Rasmussen.“ Effects of Juglone on Growth, Photosynthesis and Respiration.” The Journal of Chemical Ecology. March 1993, Vol 19, Issue 3, pp 559-568. Sprinker link. Web. 04 November. 2014.

“Black Walnut: Juglans nigra” 4-H Forest Resources. Environmental Education at SFFC, n.d. Web. Nov 06 2014.

Bonnie Appleton, Roger Berrier, Roger Harris, Dawn Alleman, and Lynnette Swanson. “The Walnut Tree: Allelopathic Effects and Tolerant Plants”. Virginia Tech Dept. of Horticulture, Norfolk VCE, and Chesapeake VCE. Virginia Cooperative Extention. Web 04 Nov. 2014.

Canada. Dept. of Environment. Species at Risk Public Registry: Butternut. Ottawa. mod. Oct. 21 2014. Web. Nov 06 2014.  

“Growing Hardwoods: About black walnut”. Walnut Council. Write Forestry Center. 2011. Edited Nov 06, 2014. Web. Nov. 08, 2014.

“Juglans nigra (F)”. Royal Horticultural Society. N.p 2014. Web Nov. 06 2014.

“Winter three identification”. Three bark ID. N.p, n.d. Web. Oct 19 2014.


Salamanders of the Morgan Arboretum

Welcome fellow salamander enthusiasts!

Some of you may already be familiar with our Twitter page (@MacSalamanders), if not, we are a group of four undergraduate students from McGill University (Montreal, QC) conducting a research project on salamanders. Salamanders and newts are amphibians within the Caudata order and belong to the Salamandridae family and Pleurodelinae subfamily, respectively [1]. Similar to frogs and lizards, salamanders have smooth and moist skin, however, newts have warty and dry skin; these characteristics are indicative of habitat and lifestyle [2]. Additionally, these vertebrates possess the ability, even in adulthood, to regenerate severed or shed limbs; this defense mechanism proves to be extremely useful against predators [3].

Blue-spotted salamander snuggling up to a red-backed salamander

Blue-spotted salamander snuggling up to a red-backed salamander

Indigenous to our data collecting zone (Morgan Arboretum, Sainte-Anne-de-Bellevue, QC), the blue-spotted salamander (Ambystoma laterale) [4], the red-backed salamander (Plethodon cinereus) [5] and the red-spotted newt (Notophthalmus viridescens) [6] are our project’s study species. Blue-spotted salamanders are nocturnal creatures which breed in swamps and ponds during the spring allowing the eggs to be laid in water [7]. The red-backed salamanders, existing in two color phases (lead back or red/orange-striped back), typically breed in the fall and females lay their eggs on rotten logs [8]. The red-spotted newts breed in the water following extensive courtship displays. Interestingly, their skin contains toxins which have proven lethal to most of their predators [9]. Lastly, these salamanders are cold-blooded and must hibernate in order to survive during the colder seasons [10].

Habitat and Distribution

Salamanders can be found underneath rocks or logs in their terrestrial stage or at the bottom of streams or ponds in their aquatic stage [11].  The blue-spotted and red-back salamanders are only terrestrial so they can be found under rocks or logs whereas the red-spotted newt lays its eggs in their aquatic stage so they can be found at the bottom of streams or ponds as well as rocks and logs [12].

There are 21 species of salamanders located in Canada and 10 of those can be found in Quebec.  A few factors that affect the distribution of salamanders are habitat modification and climate change.  As a result, the amphibians of Canada suffer greatly from decreased precipitation and elevated temperatures during the summer [13].

Video: Red-backed salamander found beneath a rock from one of our data collection zones


Red-backed salamanders hunt large and nutritious arthropods like millipedes, fly larvae, beetle larvae, and spiders [14]. They do so by thrusting their tongues quickly to entrap prey and then bring it in their mouths. Since salamanders do not like dry conditions, they will hunt more actively after a rainfall or in conditions of high humidity. When the environment dries out, they will retreat back under logs and rocks in order to stay moist. Salamanders eat as much as they can in favorable conditions and store the extra food as fat which is burned when the salamanders catch less prey, allowing them to survive in more scarce conditions [15].

Importance to Ecosystems

The salamander is important in monitoring the wellbeing of an ecosystem. Because of their sensitivity to ecological changes, tracking the salamander population over time allows us to observe many other important factors of ecosystem wellbeing. This includes moisture cycling, the dynamics of the foodweb, succession, and general biodiversity. Because of their abundance and the relative ease at which they can be found, the salamander is often considered somewhat of a “canary in a coal mine”, and for this reason have much importance in their ecosystem [16].

Potential staring contest between two red-backed salamanders!

Potential staring contest between two red-backed salamanders!

Our Project

Research question – What environmental parameters (forest type, soil temperature, and preferred coverage) can be associated with the highest density of salamanders in the Morgan Arboretum?


For our research project, we sampled areas within deciduous forests, coniferous forests, and mixed forests.  We set up 10 meter by 10 meter quadrants where we would collect all our data.  We sampled each quadrant by starting in one corner of the collecting zone and moving outwards flipping over rocks and logs within that area searching for salamanders.

Part way through our data collection, we began to sample differently since in some quadrants 0 salamanders were found compared to other areas where we found close to 20.  To ensure we could collect data, we would first look under rocks and logs until we found a salamander.  Once we discovered a salamander, we set up our collecting zone around it.  This guaranteed a minimum of 1 salamander per quadrant.

Problems Faced

Over the course of our data collection period, we encountered several obstacles we had to work around in order to ensure the accuracy of our data. Our first hurdle occurred as we first ventured into the Morgan Arboretum: we hadn’t anticipated for the ground to be so covered with fallen leaves and other organic matter. As a result, it was much more difficult to locate salamanders as opposed to just a few weeks prior, when all the leaves were still on the trees. We adjusted our methods to include a “sweeping” step, where we temporarily cleared the leaf cover off the areas we were sampling to ensure that no rock or log went unturned.

Baby red-backed salamander hiding within the fallen leaves

Baby red-backed salamander hiding within the fallen leaves

We soon found that without a proper protocol in place, it was possible for different team members to find the same salamander at different times, but count it as two separate specimens. To prevent overcounting, we established a system where whenever one team member found a salamander, we would all converge to record data and take note of where exactly it was found. We also took photos of each salamander and where it was found for our own reference.

Another challenge we faced was that we were sometimes not physically strong enough to flip over a large log or a rock. This created the possibility of undercounting the population, as it was still possible for salamanders to be hiding under these bigger objects. Unfortunately, we had no way of countering this obstacle with our equipment at hand. Instead, we will keep this in mind when we complete our data analysis, and evaluate how this could affect our final result.



  1. Koremiak DA, Govardovskii VI: [Photoreceptors and visual pigments in three species of newts]. Zhurnal evoliutsionnoi biokhimii i fiziologii 2013, 49(4):264-271.
  2. Amphibians; Salamander and Newt [http://animals.sandiegozoo.org/animals/salamander-newt]
  3. McCusker CD, Gardiner DM: Understanding positional cues in salamander limb regeneration: implications for optimizing cell-based regenerative therapies. Disease models & mechanisms 2014, 7(6):593-599.
  4. Noël S, Labonté P, Lapointe FJ: Genomotype frequencies and genetic diversity in urban and protected populations of blue-spotted salamanders (Ambystoma laterale) and related unisexuals. Journal of Herpetology 2011, 45(3):294-299.
  5. Moore JD: Short-term effect of forest liming on eastern red-backed salamander (Plethodon cinereus). Forest Ecology and Management 2014, 318:270-273.
  6. Strain GF, Turk PJ, Anderson JT: Functional equivalency of created and natural wetlands: diet composition of red-spotted newts (Notophthalmus viridescens viridescens). Wetlands Ecology and Management 2014.
  7. Blue-spotter Salamander (Ambystoma laterale) [http://www.ontarionature.org/protect/species/reptiles_and_amphibians/blue-spotted_salamander.php]
  8. Eastern Red-backed Salamander (Plethodon cinereus) [http://www.ontarionature.org/protect/species/reptiles_and_amphibians/eastern_red-backed_salamander.php]
  9. Eastern Newt (Notophthalmus viridescens viridescens) [http://www.ontarionature.org/protect/species/reptiles_and_amphibians/eastern_newt.php]
  10. Salamander [http://www.thecanadianencyclopedia.ca/en/article/salamander/ ]
  11. Hawkins CP, Murphy ML, Anderson NH, Wilzbach MA: Density of Fish and Salamanders in Relation to Riparian Canopy and Physical Habitat in Streams of the Northwestern United States. Canadian Journal of Fisheries and Aquatic Sciences 1983, 40(8):1173-1185.
  12. Kristin P, Gvozdik L: Aquatic-to-terrestrial habitat shift reduces energy expenditure in newts. Journal of experimental zoology Part A, Ecological genetics and physiology 2014, 321(4):183-188.
  13. Alford RA, Richards SJ: GLOBAL AMPHIBIAN DECLINES: A Problem in Applied Ecology. Annual Review of Ecology and Systematics 1999, 30(1):133-165.
  14. Wyman RL: Experimental assessment of salamanders as predators of detrital food webs: effects on invertebrates, decomposition and the carbon cycle. Biodiversity & Conservation 1998, 7(5):641-650.
  15. Plethodon cinereus [http://animaldiversity.ummz.umich.edu/accounts/Plethodon_cinereus/]
  16. Welsh HH, Droege S: A case for using plethodontid salamanders for monitoring biodiversity and ecosystem integrity of North American forests. Conservation Biology 2001, 15(3):558-569.




Beech Bark Disease

The American Beech Tree

The American Beech, by its scientific name Fagus grandifolia, is a deciduous tree native from Nova Scotia. F. grandifolia holds an important role in forestry since its nuts constitute an element of the diet of several species, including humans. Furthermore, due to its hard, heavy and strong wood, Beech trees are a material of choice. Therefore, it also has an economic importance (Tubbs & Houston, 2001)

Beech that shows nuts and leaves

Beech that shows nuts and leaves (Image sources: here  and here)

The Disease

In 1849 a severe disease affecting the American Beech appeared in Europe named Beech bark disease (BBD). Around 1890 BBD was accidentally introduced in Nova Scotia, spreading over most of the North America. BBD, which is now a big threat to North American forests, is the result of an interaction between an insect and a fungus.

The beech scale insects can be recognized by the white wax that they produce for protection, which appear as small white points. They live on Beech bark and feed with their stylet which penetrate the bark and give them access to the sap, creating billions of tiny holes. These holes then stay open due to a substance produced by the scales.

bark with scales

bark with scales (Image source: here)

This large amount of tiny holes constitutes a good environment for the fungi to live, which arrive on the bark as spores transported by wind or rain. The fungi could be Neonectria faginata or Neonectria ditissima, both easily recognizable by their small rounded shape and red color. They attack the bark by creating lemon shaped cankers (around two centimeters in diameter) in each infested wound.

Beech with fungi

Beech with fungi

The disease weakens the wood which leads to difficulties in water circulations and it makes the trunk more likely to break by wind pressure (Lavallé & Laflamme, 2010). Thus, a Beech with a severe infection could present a lower amount of smaller leaves and a large number of cankers infested with little red bubbles on its bark. In most cases, BBD leads to tree death.

Edge Effect

Edge effect can be described as the change in ecosystem structure occurring at the boundary between two habitats. The most pronounced edge effects in forests such as the Morgan Arboretum are caused by trails. They fragment the ecosystem in several sections and can ultimately change it by altering several different factors such as soil, wildlife and plants (Ballantyne, 2014). These factors are impacted not only by the trails themselves but also the increased human traffic. Some commonly researched problems are the introduction of foreign species in these new habitats (Indiana University, 2011) and compaction and erosion of the soil by increased human activity in the forest (e.g. joggers, domestic animals or cars). Other problems include these same activities interfering with the natural habitat of flora and fauna. Included in this, trail networks with high human usage can increase the spread insects and spores through physical and wind dispersal. These are all relevant when looking at the edge effect at the Morgan Arboretum.

These factors could all potentially contribute to changing the surrounding forest. Knowing that trails can cause such edge effects, we wished to study how trails affected BBD and more specifically, if BBD was most severe along trails.

Tree Diversity

The other factor considered in our research question is the influence of tree diversity on the severity of BBD. Tree diversity is influenced by both the number of different species present and the number of trees growing of each species. A forest or tree stand (an area sharing common borders, age and tree diversity) is considered to be Beech dominant if it is composed of around 50% Beech trees or more (McCullough et al., 2005). Previous studies have shown that the age and density of the stand, as well as the tree sizes and the diversity of tree species composing it will have an effect on the severity of the disease. Tree mortality worsens in older stands with numerous mature beech trees. (Houston, 1998).

Having trees of other species surrounding these beech trees can serve them as a buffer against stressors (Grondin & DesRochers, 2013). When managing a stand, either threatened by the incoming of the beech scale or already affected by it, specialists recommend increasing tree diversity which may help in reducing the spread and reproduction of the scale insect. (McCullough et al., 2005). Also, reducing the number of older large beech trees will “lessen the impact of the disease once it reaches the stand” (Grondin & DesRochers, 2013).

Tree diversity has been found to buffer the spread of BBD in highly diverse forests. To assess whether this was applicable in the Arboretum and, if so, how edge effects from trails could alter this buffer, we chose to sample in forest stands with different levels of diversity.

Research Question

What is the impact of edge effects produced by Arboretum trails on the distribution of BBD by comparison of three different forest stands: Beech, Beech/Red Maple and Hemlock/Beech/Red Maple?

Research Methods

In order to assess the impact of edge effect on the distribution of BBD, we chose three forest types to study based on their increasing amount of diversity: Beech, Beech/Red Maple and Hemlock/Beech/Maple. This allowed us to assess any correlation between edge effect and diversity (i.e. if diversity lessens the spread of BBD). Within each forest type, we sampled beech within quadrats measuring 10mx10m along transects at a 90 degree angle from the trail. Quadrats within transects were 20m apart, the first quadrat located trailside. In addition, transects were separated by 10m to cover more forest area and make sure no trees were counted twice. Overall, 9 quadrats were sampled in each area. For every Beech tree we measured diameter at breast height (DBH) in centimeters, and the severity of: scales, cankers, fungi, and bark loss. The severity of each characteristic was rated on a scale of 0 to 2, 0 being absent/non=severe and 2 being present/severe. From this, a total score was calculated for each tree indicating BBD severity on a scale of 0-8. In this way, each quadrat could be analyzed for its average BBD severity. This allows us to more accurately depict whether or not the edge effects from the trail are positively affecting distribution of the BBD (i.e. helping to spread the disease).

Group pictures

Group pictures


Ballantyne, M., Gudes, O. & Pickering, C. M. (2014). Recreational trails are an important cause of fragmentation in endangered urban forests: A case-study from Australia. Science Direct, 130, 112-124. Retrieved from http://www.sciencedirect.com/science/article/pii/S0169204614001595 Date accessed 05/11/14

Fernald & Rehder. (1997). Flora of North America. Volume 3. Page 1788.

Lavallé, R. & Laflamme, G. (2010). Le hêtre menacé par une maladie redoutable en Amérique. Progrès forestier. Printemps 2010. Page 31-33.

Predicting Invasive Species Spread: Spread of Invasive Species (2011). Retrieved from http://www.indiana.edu/~preserve/InvasiveSpread/. Date accessed: 05/11/14.

Tubbs, C.H. & Houston, D.R. (2001). Silvics of North America. Volume 2: Hardwoods. Page 330.

Weaver T. & Dale D. (1978). Trampling Effects of Hikers, Motorcycles and Horses in Meadows and Forests. Journal of Applied Ecology, Vol. 15 no. 2, 451-457. Retrieved from http://www.jstor.org/stable/2402604?seq=5. Date accessed: 05/11/14.

Grondin, J., and DesRochers, P. “Beech Bark Disease.” Natural Resources Canada. Government of Canada, 11 Dec 2013. Web. 5 Nov 2014

Houston, D.R. “Beech Bark Disease” North Central Research Station, USDA Forest Service, 1998. Web. 5 Nov 2014

McCullough, Deborah G., and Heyd, Robert L., and O’Brien, Joseph G. “Biology and Management of Beech Bark Disease.” Michigan State University Extension, Extension Bulletin E-2746. (Reprinted 2005): Page 7. Print.


Bird Diversity at the Morgan Arboretum

Birds come in a wide variety of species, each with its own distinctive colours, calls and behaviours. While some birds’ lifestyles cause them to enter in direct competition with others, such as two species competing for the same nesting sites, other groups may avoid such conflicts by adapting to different food sources and habitats. In the Saint-Lawrence Lowlands, these habitats can be broken down into two main forest types: deciduous and coniferous. Between these two forest types, some bird populations may be more diverse than others. Therefore, through our research at the Morgan Arboretum, we wish to see if there is a correlation between forest type and bird diversity.

Figure 1. Snow Buntings forage for food in our study site, the Morgan Arboretum.

Figure 1. Snow Buntings forage for food in our study site, the Morgan Arboretum.

Bird Diversity

Diversity is the measurement of the abundance of individuals and the variety of species in an area. A place with more species in greater numbers has a higher diversity, and vice-versa. A less diverse area could have one species that is more common because it outcompetes other birds, and limits the total number of species encountered (1).

For our research, the relative abundance of various birds within each forest type will be noted and should tell us which forest has higher bird diversity. According to the study by MacArthur et al. 1961, birds may either prefer specific forest habitats (and live off of resources unique to that habitat) or they may all live in one large habitat and have specialized ways of living for specific situations (2). Birds showing preference for one type of forest will increase the diversity in that area, but some other bird species might be equally abundant in both places, causing neither forest to be more diverse than the other.

Figure 2. A Barred Owl rests in a conifer at the Arboretum. This species enjoys coniferous and deciduous woods.

Figure 2. A Barred Owl rests in a conifer at the Arboretum. This species enjoys coniferous and deciduous woods.

There are many reasons why one forest may attract more species than another. Factors such as vegetation and the physical structure of the trees may influence food sources and provide protection from predators and also the best nesting sites. These may contribute to a forest’s ability to attract more birds (1). For example, coniferous forests provide shelter in winter with their pine needles and their cones and seeds are present throughout the year, offering overwintering birds important food sources. On the other hand, deciduous forests provide more fruit variety during certain seasons, attracting greater numbers of birds.

A previous study by James and Rathbun in 1981 (3) showed that coniferous forests supported the lowest diversity of bird species, as did a later study in 1996 by Willson and Comet (4). The overall trend seems to show that deciduous stands support a greater amount of avian species.

Figure 3. The two main forest types. Left: A stand of coniferous trees. Right: Deciduous forest

Figure 3. The two main forest types. Left: A stand of coniferous trees. Right: Deciduous forest


The general public is often not aware of the importance of bird diversity. Birds, admired for their beauty and wonderful songs, are often welcomed in parks or backyards, as humans enjoy their wonderful spirit and magnificent colors. However, not only are they beautiful, they are also excellent environmental indicators. A habitat’s good health can be implied by the presence of birds (5). They help pollinate and disperse seeds and many naturalists refer to them as “agents of dispersal” (6).  Additionally, birds control pest levels by the sheer number of insects and mice various species consume (6). For these reasons, having a high bird diversity in any given forest is important for the environment’s overall health, and studying bird diversity is a good way to gain knowledge of the forests that they live in (5).

Examples of Study Species

As we are looking at the overall bird diversity in each forest type, our study species will include every bird noted during our data collection. One of the most common birds seen are Blue Jays. This species often hangs around forest edges, and breeds in both coniferous and deciduous woods. They have distinctive blue, white and black plumage, and use a complex communication system with a large variety of calls (7).

Figure 4. A Blue Jay eyes the photographer before moving on its way in coniferous forest.

Figure 4. A Blue Jay eyes the photographer before moving on its way in coniferous forest.

The call of the Black-Capped Chickadee is as equally common. This songbird has a black cap and black bib, white cheeks and grey and white feathers covering its round body. They are found all around North America, but their preferred habitat is deciduous and mixed forests (7).

Figure 5. In coniferous, a Black-capped Chickadee looks for its next perch.

Figure 5. In coniferous, a Black-capped Chickadee looks for its next perch.

Another forest-loving species that we hoped to see is the White-breasted Nuthatch, a songbird with a black cap and back plumage of a grey-blue color. This bird is territorial and it is usually more abundant in deciduous forests than in coniferous ones (7).

 Figure 6. White-breasted Nuthatches move down trees looking for insects

Figure 6. White-breasted Nuthatches move down trees looking for insects

It is probable that the most commonly seen woodpecker will be the Downy, which is the smallest woodpecker in North America. They have a relatively short bill compared to their body size, their plumage is black and white and the males have a small red patch on the back of their head. This woodpecker breeds mainly in deciduous forests (7).

Birds Figure 7

Figure 7. A Downy Woodpecker examines a tree by pecking at the bark


We selected three replicates of deciduous forest and three of coniferous forest, each of 50mx50m, and at least 50m apart from each other. We split up in two teams, one for each type of forest, changing the people in each team and the order in which we visited the replicates to ensure the process was as unbiased as possible.

We spent 10 minutes of quiet time in each replicate during which we did not include the birds seen or heard in our data, then we spent 30 minutes bird watching. During these 30 minutes, every bird seen or heard within the range our our replicate was included in our data, but traces of birds (pellets, woodpecker holes, etc.) were not. Time of day and weather conditions were also logged.

Figure 8. Map of areas used in Morgan Arboretum. C = coniferous  D = deciduous

Figure 8. Map of areas used in Morgan Arboretum. C = coniferous D = deciduous


(1) Gill, F. (1995) Ornithology (2nd ed.). New York: W. H. Freeman and Company.

Available from: http://www.jstor.org/stable/1932254

(2) MacArthur, R. & MacArthur, J. (1961). On bird species diversity. Ecology,
: 594-598.

(3) James, F. & Rathbun, S. (1981). Rarefaction, relative abundance, and diversity of avian communities. The Auk, 98: 785-800. Available from: https://sora.unm.edu/sites/default/files/journals/auk/v098n04/p0785-p0800.pdf

(4) Willson, M. & Comet, T. (1996). Bird communities of northern forests: ecological correlates of diversity and abundance in the understory. The Condor, 98: 350-362. Available from: https://sora.unm.edu/sites/default/files/journals/condor/v098n02/p0350-p0362.pdf

(5) Birds as Indicators of Sustainability. Birds in Backyards. Web. http://www.birdsinbackyards.net/birds/Birds-Indicators-Sustainability

(6) The Importance of Birds. Iowa NatureMapping. Web. http://www.extension.iastate.edu/naturemapping/monitoring/importance_birds.htm

(7) Cornell Lab of Ornithology, Cornell University,
Web. http://www.birds.cornell.edu/Page.aspx?pid=1478  Nov. 06 2014.

Further Reading on Birds and Bird Diversity:





Salamanders: their natural history and our research

Salamanders belong to the Caudata order. Along with Anura (frogs) and Gymnophiona (caecilians), they belong to the Amphibian group (Bishop 1943). Salamanders are often confused with lizards because of their similar body form but they lack scales. Instead salamanders have moist glandular skin that is permeable to water and unlike frogs, they have tails and teeth in both jaws (Bishop 1943). They rely on moisture to survive and can disappear when there is no rainfall (Bishop 1943).

The three salamanders found in the Morgan Arboretum are the blue-spotted salamander (Ambystoma laterale), the red-spotted newt (Notophthalmus viridescens), and the red-backed salamander (Plethodon cinereus). The red-spotted newt lays its eggs in water and spends its adult life in water but juveniles, called “red efts” can be found on land. On the other hand the red-backed and blue-spotted salamanders are terrestrial and lays egg in damp logs (Bishop 1943). The red-backed salamander has two color polymorphisms. Typically a red-dorsal stripe is present but without, it is called the lead-back phase. Predators are more likely to attack the lead-back phase. (Davis 2010).

Lead back phase (L) and red back phase (R) of the red back salamander

Lead back phase (L) and red back phase (R) of the red back salamander

Distribution and habitat

There are only two continents on which salamanders do not occur: Antarctica and Australia. Most species of salamanders are found in North and South America. Indeed, eight of the nine families of salamanders are found in North America and four of these families (Proteidae, Ambystomatidae, Salamandridae, Plethodontidae) occur in Canada (Aartse-Turyn M. et al).

We have twenty-one native species in Canada and ten of them are found in the province of Québec (Gorham and Cook; Redpath museum). Usually, they are found under logs or rocks in the forest and aquatic species are found at the bottom of streams and ponds under stones and detritus (Aartse-Turyn M. et al). Research has shown that management of the forest, vegetation and landscape characteristics are factors that influence the distribution of salamanders (Harper A. and Guynn D 1999). As salamanders need high amounts of calcium they prefer habitats where deciduous trees can be found (Harper A. and Guynn D 1999).

Red spotted newt

Red spotted newt


Depending on their size, salamanders feed on arthropods, gastropods, earthworms or even tadpoles and smaller salamanders (Gorham and Cook). However, as previously mentioned, salamanders need high amounts of calcium which is why they prey mostly on small scavengers such a snails (Harper A. and Guynn D 1999).

Importance to Humans

Salamanders are crucial to humans both culturally and scientifically. Many wrongly neglect the cultural significance as proof of importance to humans because it doesn’t represent any economic or scientific value. Salamanders appear in many myths around the world and most associate them with fire. People believed that salamanders were born or created from fire because of their sudden appearance amid flames when a fire was lit. Many, including Pliny the Elder, also thought that their cold skin could extinguish fire and even that the skin and other parts gave protection against flames (Pliny the Elder, AD. 77-79). As a result of these beliefs, salamanders represented courage, passion, loyalty, etc and therefore were used as symbols in heraldry.

From a scientist’s point of view salamanders are key in understanding an extraordinary phenomena which would revolutionize medicine : limb regeneration. Indeed, salamanders are the highest order of animals capable of regenerating body parts, including their tails, upper and lower jaws, eyes and hearts (Conger, 2008). Research lead by Dr Goodwin, of the Australian Regenerative Medicine Institute has shown that this ability relies on their immune system (precisely their macrophage cells). It has been proven that most organisms (including humans) possess the potential of limb regeneration in their genes, but those genes are dormant due to evolution (Kotulak, 2006).

Red backed newt

Red backed newt

Our project

Research Question – What environmental indicators are correlated with the presence of salamanders in the Morgan Arboretum?

For our research project, we are sampling one area within the Morgan Arboretum where salamanders are known to occur. Our data collection method was relatively simple. We started at the same location each week and then walked 150 metres into the forest. From here, we walked in a randomly selected direction for 50 metres. A 10-metre x 10-metre quadrat was established in this location and then we flipped all the logs within the quadrat. Under each log we searched for salamanders and then measured environmental variables of the microhabitat such as temperature, soil moisture and amount of leaf litter.

Problems we’ve faced

Our original research question focused around the availability of suitable salamander habitat in the Morgan Arboretum, as we were unsure as to the likelihood of finding salamanders in our study site. We were thus inclined to study salamanders indirectly by looking at their likely distribution through the presence of suitable habitat. However, after our first visit to the Morgan Arboretum, during which we found eight salamanders in less than three hours, it became apparent that there were more salamanders in the Arboretum than we previously had thought. Therefore, we were able to study salamanders in a more direct way rather than simply looking at areas, which could be potential habitat for the amphibians. Consequently, we changed our research question to be more focused on the environmental conditions that were good predictors of the presence or absence of salamanders. By measuring the microhabitats under logs where there were/ were not salamanders allows us to compare the two scenarios to examine which factors are greatly correlated to salamander presence.

During our data collection, we are often faced with the challenge of flipping extremely heavy logs. Sometimes we succeed, yet sometimes we don’t. This means that we are sometimes not able to sample all the logs in our quadrats and may be underestimating the abundance of salamanders in the Arboretum. It is unclear how this will affect our results.

For more information on the amphibians found in the Morgan Arboretum:


Data collecting in the Arboretum

Data collecting in the Arboretum


Amphibians and reptiles of Quebec [Internet]. 1999. Montreal (Qc); Redpath museum (McGill University); [updated 1999 March; cited 2013 Oct 22]. Available from:http://redpath-museum.mcgill.ca/Qbp/herps/herps.html

Bishop, S.C. 1943. Handbook of Salamanders. Comstock Publishing Company, Inc., Ithaca, New York. Web.

Caudate families [Internet]. 2010. Place of publication not available ; Aartse-Turyn M., St. Laurent R., Macke J. and Williams J. ; [uptated 2010 April ; cited 2013 Oct 22]. Available from:http://www.caudata.org/cc/species/species.shtml

Conger, C. 2008. How can salamanders regrow body parts?

Davis, AK. 2010. ”Lead-phase and red-stripe color morphs of red-backed salamanders Plethodon cinereus differ in hematological stress indices: A consequence of differential predation pressure?” Current Zoology, 56, 238-243.

Gorham SW, Cook  FR. Salamander  [Internet].Canadian Encyclopedia ; [cited 2013 Oct 22] . Available from: http://www.thecanadianencyclopedia.com/articles/salamander”http://www.thecanadianencyclopedia.com/articles/salamander

Harper A. & Guynn D. 1999. “Factors influencing density and distribution within four forest types in the Southern Appalachian Mountains” Forest ecology and management, 114, 245-252

Kotulak, R. 2006. Research brings hop body parts can regrow. Knight Ridder Tribune Business News.

Pliny the Elder. AD 77–79. Naturalis Historia. (Book 10, 86)


Meet the Norway Maple (Acer platanoides)

Kingdom : Plantae
Order: Sapindales
Family: Sapindaceae
Genus: Acer
Species: A. plantanoides

The Norway Maple team performed their research on a small spatial scale in the Morgan Arboretum’s Maple Corner. Maple Corner is the site of introduction of the species to the Arboretum, as eight individuals were planted there in the 1950s.

The Norway Maple team performed their research on a small spatial scale in the Morgan Arboretum’s Maple Corner. Maple Corner is the site of introduction of the species to the Arboretum, as eight individuals were planted there in the 1950s.

A species native to Europe, the Norway Maple (Acer platanoides) is a deciduous tree now commonly found throughout the St. Lawrence Lowlands, including McGill University’s Morgan Arboretum. In appearance, the Norway Maple is quite similar to other trees of the genus Acer, including Acer saccharum, the Sugar Maple (7). However, the Norway Maple exhibits various distinguishing traits in terms of its physiology. Norway Maple leaves have between five and seven lobes and are both wider and longer than their Sugar Maple counterparts (8). In addition, Norway Maple buds appear wide and reddish-brown in color as opposed to the pointy, brownish-green buds of Sugar Maples (7). A white sap will also ooze from the petioles of Norway Maple leaves upon breakage (7).  Furthermore, these trees will retain their leaves longer than Sugar Maples due to their prolonged growing season, and thus Norway Maple leaves do not transition from green to yellow to brown until after the Sugar Maples have progressed through their red-brown colors (7). In terms of its bark, a Norway Maple trunk is smooth and grey in color at a young age and will develop shallow furrows over time (3).

Though of the same genus as the Sugar Maple, the Norway Maple possesses several distinguishing characteristics. They differ from other maples in leaf and bark physiology, bud structure, and even the presence of certain diseases.

Though of the same genus as the Sugar Maple, the Norway Maple possesses several distinguishing characteristics. They differ from other maples in leaf and bark physiology, bud structure, and even the presence of certain diseases.

The species’ natural range is widespread across Europe and West Asia, extending from northern Spain east to the Ural Mountains of Russia, and from southern Scandinavia southwards over the European continent (9). The Norway Maple possesses many desirable traits that contributed to its early popularity and thus its introduction to North America (9). The species maintains a robust growth rate and the ability to thrive in varied soil types (9). In addition, the species is especially tolerant of normally restrictive conditions, including polluted air and soils with high acid or salt content (5).

The aforementioned factors bolstered the success of A. platanoides when it was intentionally introduced to North America in the 1700s for ornamental purposes (10). Farms and towns began cultivating these especially hardy trees for shade, further expediting the invasion of Norway Maples across the Eastern seaboard of the United States (10). Consequently, its current range stretches from Maine down to Tennessee and west to Wisconsin (10).  In Canada, the extent of the trees encompasses land from Newfoundland to southern Ontario, as well as the southern portion of British Columbia (4). The species is a prominent inhabitant of the St. Lawrence Lowlands of Quebec; in the 1950s, eight Norway Maples were planted in the Morgan Arboretum, where they continue to thrive in competition against tree species native to the region.

Overall, the presence of Norway Maples is detrimental to native flora and fauna of a given region. This species is prone to growing in dense stands that create excessive shade, thus preventing the growth of native seedlings that require more sunlight (4). An especially shallow root system further hinders the establishment of native trees in a localized area (4). These characteristics allow for the Norway Maples, which have no natural predators in their new North American environment, to outcompete native species, such as the Sugar Maple (4). This dominance displayed by the Norway Maples also impacts native fauna; species including white-tailed deer and moose browse on Sugar and Red Maples, so the loss of these trees to the Norway Maple may threaten animal biodiversity, as well (1).

Various methods have been devised and implemented to control the growth of the highly invasive Norway Maples. Mechanical methods include pruning limbs that bear seeds while leaving the trunk, or girdling larger, more established individuals (6).  Girdling is a process in which a ring of cork cambium is cut from the lower trunk, preventing transport of water and nutrients throughout a specimen and killing it over the course of a few growing seasons (6). Nevertheless, girdling alone may not be sufficient; application of tryclopyrs and glyphosphate herbicides may be necessary to expedite the death of the tree (6). Smaller saplings may instead be uprooted directly from the soil with a weed wrench (6). However, the most effective method of control is to avoid planting Norway Maples and to instead plant native varieties that will not negatively impact the environment (6). In 2007, a study was completed that suggested management methods to control invasion. Environment Canada and a team of students promoted manually cutting and applying herbicides to the trees, as well as establishing a buffer zone free of Norway Maples to contain their invasion to a concentrated location (2). The team found that this would help prevent the spread of Norway Maples via wind dispersal of seeds, especially due to the eastward prevailing winds (2).

Girdling is a form of invasion control that has been implemented in the Morgan Arboretum. Note that a ring of cork cambium has been removed from each of these individuals, thus preventing transport through the tree and resulting in its death.

Girdling is a form of invasion control that has been implemented in the Morgan Arboretum. Note that a ring of cork cambium has been removed from each of these individuals, thus preventing transport through the tree and resulting in its death.

The invasiveness of Norway Maples can be observed on a small scale in the Morgan Arboretum located at McGill University’s Macdonald Campus. The remaining stumps of the eight originally cultivated trees are located in a concentrated sector of Maple Corner within the Arboretum. The proposed research question is to measure the invasiveness of the Norway Maples from the site of introduction into the surrounding forest. From the origin, transects consisting of 5X5 meter quadrants extend into the forest in the four cardinal directions. Some transects are shorter than others due to natural barriers such as edges between fields and other stands of trees. However, the general method remains consistent; in alternating quadrants along a particular transect, the number of Norway Maple individuals is recorded, along with the trunk diameters of the sizeable specimens. Additional notes, including observations regarding ground cover or the presence of girdling, are also documented. Through this method, it is possible to study the infiltration of Norway Maple trees as they expand from their site of introduction into a forest of Sugar Maples and other species native to the St. Lawrence Lowlands.

    (Click image to view larger map) Map displays the location of the eight original Norway Maple trees in the Morgan Arboretum, as well as the transects that were used to measure the invasion of the species into the forest from the site of introduction.

(Click image to view larger map) Map displays the location of the eight original Norway Maple trees in the Morgan Arboretum, as well as the transects that were used to measure the invasion of the species into the forest from the site of introduction.


 1. Abbey T. 2000. Invasive plant information sheet. CT agriculture experiment station [internet]. [cited 2013 Oct 22] 85(1):69. Available from: www.cipwg.uconn.edu/pdfs/norway_maple.pdf

2. Beauregard, F. and C. Idziak. 2008. Norway Maple Invasion in the Morgan Arboretum, Ste.-Anne-de-Bellevue, QC. Report Ecological Monitoring and Assessment Network, Environment Canada p.44

3. Coombes AJDZ. The book of leaves : a leaf-by-leaf guide to six hundred of the world’s great trees. Chicago; London: The University of Chicago Press; 2010

4. Growing better places to live [internet]. 2013 [place of publication unknown]: TreeCanada.ca; [updated 2013 Jul 16; cited 2013 Oct 22]. Available from: http://treecanada.ca/en/resources/tree-killers/plants/norway-maple/

5. Hiwassee River Watershed Coalition, inc [internet]. 2004 [Place of publication unknown]: hrwc.net; [updated 2013 Feb 13; cited 2013 Oct 22]. Available from: http://www.hrwc.net/norwaymaple.htm

6. Love R. [internet]. 2003. Introduced species summary project. [Place of publication unknown]: Conlumbia.edu. [updated 2003 Feb 17; cited 2013 Oct 22]. Available from: http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Acer_platanoides_2.htm

7. More DWJ. Illustrated trees of Britain & Europe. 2013

8. North America, Native Plant Society [internet]. 2001 [Place of publication unknown]: nanps.org; [updated 2013 Oct ; cited 2013 Oct 22]. Available from: http://www.nanps.org/index.php/conservation/alien-invaders/103-joyston

9. Nowak DJ. History and range of Norway maple. Journal of arboriculture 1990;16(11):291

10. Swearinger J. 2010. Plant invaders if mid-Atlantic Natural areas [internet]. Washington (DC): National Park Service; [cited 2013 Oct 22]. Available from: http://www.nps.gov/plants/ALIEN/pubs/midatlantic/acpl.htm


Pileated Woodpecker whereabouts in the Morgan Arboretum

Research Question

In order to to investigate where the Pileated Woodpecker (Dryocopus pileatus) is predominantly found within the Morgan Arboretum and whether they have a preference in area or tree they target, we asked ourselves the following question. “Is the Pileated Woodpecker (Dryocopus pileatus) more active (excavate more trees) in certain parts of the Morgan Arboretum, and does this activity correlate with a dominant tree type?”wp1

From our research on the Pileated Woodpecker, we found that they are said to nest in large, dead trees and feed predominantly on insects (Bull 1987). In one study, it was noted that Pileated Woodpeckers predominantly avoided young trees and preferred more mature ones for foraging (Savignac et al. 2000).

From this, the objective of our project was to see if our results concurred with those of the different scientific studies of the past. Seeing as there were no known studies exactly like ours, we also attempted to find results that are region specific to the Morgan Arboretum. Our goal was to determine whether the Pileated Woodpecker is more dominant in one area of the Morgan Arboretum and to see whether it has a preference in a certain family of tree.


In order to study the Pileated Woodpecker the Arboretum was divided into 12 unique sectors each of which has different dominant tree types. Transect lines were then plotted on the map so that each sector had a total of 480m of transects within it. This was predominantly achieved by using six transects of 80 m, each 40 meters apart from each other. In the field, these transects were then walked along and any trees with Pileated Woodpecker excavation damage within 10 m of the transect were recorded. Multiple measurements were taken including diameter at breast height, the tree’s status (alive, dead or dying), GPS coordinates, tree family as well as any relevant notes about the area. All transects were carefully plotted so that no two transects intersected, or certain areas were surveyed more than others. Data was collected and entered into the mobile application iNaturalist.

Update [21/11/13]: A map showing the distribution of woodpecker work in the Arboretum is now available.

Physical Traitswp2

The Pileated Woodpecker is a recognizable bird with its large size and red crest on it’s head. Its body and wings are mostly black with white stripes down its neck.  The males have a red mustache while females a black one. They have a strong stout bill, a muscular body, and an air encased brain and fortified skull which helps them produce holes for foraging and nests (Benyus 1989).


The Pileated Woodpecker communicates with both instrumental and vocal sounds, along with physical displays. Instrumental can be drumming, drum tapping or rapping their bills. Their vocalizations (known as  “wok”s) can express a variety of of things by varying in speed, pitch and tonality. Dominance of an area, attempts to attract mates, and alarm calls are some examples of these calls. These territorial birds express dominance with sounds and conflict can occur with full-wing threat displays and air grappling. They also communicate with bill waving and crest raising (Kilham 1959).


The Pileated Woodpecker starts breeding at one year of age and lives monogamously. The clutch size ranges from three to five eggs with one brood each summer. Both sexes excavate a nest that has an entrance that is just big enough to enter and is 25 to 60 cm deep (Hoyt 1957). The incubation period is between 15 to 18 days and both parents alternate with the male having the responsibility at night. Both parents feed the hatchlings but the male still has the task of night brooding. The altricial young can fly after 24 to 28 days, but remain close to the nest, during which the parents teach them to forage, until the fall when the young disband (Hoyt 1957; Bull 1988).


Like most birds, the Pileated Woodpecker has seasonal eating habits. About 75% of the year is spent eating insects while the other 25% is mostly spent eating fruits and wild nuts. wp3During the fall, the Pileated Woodpecker tends to eat more fruits and wild nuts. After fall has passed, they spend the rest of the year mostly feeding on insects like the carpenter ant (Camponotus spp.) which is commonly found in beech and pine trees.  The woodpecker excavates these trees to extract the deep-dwelling ants inside as well as beetle larvae, which are found closer to the surface. To find food they listen for the movement of the insects with their excellent sense of hearing. The excavations of the Pileated Woodpecker are very distinct. Unlike smaller woodpeckers, the Pileated Woodpecker makes rectangular excavations that can be 30 cm or more in length. Come summertime the woodpecker has a more varied diet including fruits, berries and insects (Hoyt, 1957).


As for predators, the adult Pileated Woodpecker is preyed upon by large raptors including some hawks and owls (Bull et al. 1992). Eggs and hatchlings risk predation by a variety of mammals including American marten (Martes americana), weasel, and Eastern grey squirrel (Sciurus carolinensis) (Bull et al. 1992; Belasco 2001).


wp4These large birds prefer older growth forest for its roosts as they require a lot of space for their mates and young, and the older trees tend to be wider with larger interior diameters. Typically they prefer trees whose diameters at breast height (or DBH) are in excess of 30 cm, whether it be deciduous or coniferous (Lemaitre 2005). They are not random in their selection of trees for roosting however: most trees will have interiors that have decayed naturally, and the birds will simply create the openings and perform a bit of interior decoration, usually with wood chips (Bull 1993). They are often considered an indicator of disease in trees.


The Pileated Woodpecker is a year round resident throughout its impressive range, which spans North America from coast to coast. They can be found as far south as Florida on the east coast and as far north as the Yukon on the west coast. See here. They divert around the central mid-western United States, avoiding the great plains region bounded by the western edges of Oklahoma to Wyoming.

Want to know more? Check out The Pileated Woodpecker, on Cornell University’s All About Birds website.

Works Cited

Belasco, Jon. 2001. Pileated Woodpecker. The Virtual Nature Trail at Penn State New Kensington [Internet]. [2013 October 20]. Available from:  http://www.psu.edu/dept/nkbiology/naturetrail/speciespages/pileatedwoodpecker.htm

Benyus, J. 1989. The Field Guide to Wildlife Habitats of the Eastern United States. New York: Simon & Schuster.

Bull EL, Holthausen RS. 1993. Habitat Use and Management of Pileated Woodpeckers in Northeastern Oregon. Journal of Wildlife Management [Internet]. [Cited 2013 Oct 17] Vol 57(2): 335. Available from: http://www.jstor.org.proxy1.library.mcgill.ca/stable/3809431

Bull EL, Jackson JA. 2011. Pileated Woodpecker (Dryocopus pileatus), The Birds of North America Online [Internet].  Ithica(NY):Cornell Lab of Ornithology; [Cited 2013 Oct 19] . Available from: http://bna.birds.cornell.edu/bna/species/148

Bull EL. 1987. Ecology of the Pileated Woodpecker in Northeastern Oregon. The Journal of Wildlife Management [Internet]. [cited 2013 Oct 21]; 51(2): 472-481. Available from: http://www.jstor.org/stable/3801036

Bull, E. 1988. Breeding and Biology of the Pileated Woodpecker: Management Implications. Portland (OR): U.S Dept. of Agriculture, Forest Service, Pacific Northwest Research Station.

Bull, E.L., Holthausen, R.S., and Henjum, M.G. 2001. Roost trees used by Pileated Woodpeckers in northeastern Oregon. J. Wildl. Manage. [Internet.] [Cited 2013 October 21]

Hoyt, Sally F. April 1957. The Ecology of the Pileated Woodpecker. Ecology Vol. 38, No. 2: 246-256. [Internet]. [Cited 2013 October 20]

Kilham, L. 1959. Behavior and Methods of Communication of Pileated Woodpeckers. The Condor. 61(6): 377-387. DOI:10.2307/1365307

Lemaitre J, Villard MA. 2005. Foraging Patterns of Pileated Woodpeckers in a Managed Acadian Forest: a Resource Selection Function. Canadian Journal of Forest Research [Internet]. [Cited 2013 Oct 19] 35(10): 2387-2393. Available from: http://search.ebscohost.com.proxy1.library.mcgill.ca/login.aspx?direct=true&db=a9h&AN=19103647

Savignac C, Desrochers A, Huot J. 2000. Habitat Use by Pileated Woodpeckers at Two Spatial Scales in Eastern Canada. Canadian Journal of Zoology [Internet]. [cited 2013 Oct 21]; 78(2): 219-225. Available from: http://dendroica.ca/pdf/piwo ms.pdf


Coral and Tooth Fungi

Tooth and coral fungi are both broad categories of taxonomic classification of fungi based on physical characteristics. In fact, years of observations have shown that species in these categories are not necessarily closely related. Coral fungi, or clavarioid fungi, have coral-like elongated structures. They are rather difficult to identify due to the resemblance between many of the species. On the other hand, tooth fungi, or hydnoid fungi, are much easier to differentiate. Apart from all presenting a spine-like surface usually pointing downwards, tooth fungi can appear in a wide variety of shapes, colours and textures.

Purple coral (Clavaria zollingeri)

Purple coral (Clavaria zollingeri)

Both study groups –clavarioid fungi and hydnoid fungi –belong to the order basidiomycota. Despite their similar mechanism of reproduction, clavarioid fungi and hydnoid fungi have very distinctive physical properties.

As a group, clavarioid fungi do not belong to any natural taxon; the group solely consists of genera and species which possess a similar structure. As a physical trait, the fruit bodies of clavarioid fungi grow upwards. These fruit bodies are in the form of unbranched simple stalks or branched stalks. The stalks serve an important purpose in fungal reproduction – they elevate the spore producing cells, and increase the probability for long range dispersal. As more than thirty genera of clavarioid fungi are known – the most common of these being Ramariaidentification is extremely difficult, and must sometimes be done on the microscopic level. The colors of these fungi include white, red, orange, yellow, tan, and purple.

Spindle-shaped yellow coral (Clavulinopsis fusiformis)

Spindle-shaped yellow coral (Clavulinopsis fusiformis)

Similar to clavarioid fungi, hydnoid fungi are not taxonomically a natural taxon either, but they have a similar morphology in that their fruit bodies produce tooth-like spines (Dai 2010). These teeth-like spines grow downwards and are always orientated so that they will be exactly perpendicular to the ground. During reproduction the tapered teeth allow for the produced spores to fall straight down to the earth. Many hydnoid fungi are wood-inhabiting saprophytic species, but some of them are definitely mycorrhizas (Dai 2010). There are few species of hydnoid fungi, and even fewer common species which allows for easier identification.

Saprophytic tooth fungus (Hericium Americanum)

Saprophytic tooth fungus (Hericium Americanum)

Coral and tooth fungi both play an important role in forest ecology as species within these categories are ectomycorrhizal (i.e. many in Hydum and Ramaria genus) or saprophytic (i.e. C.pyxidata, H.coralloides, C.septentrionale) (Ostry et al. 2011).Within the last decade, more research has been centered on understanding the complex ectomycorrhizal relationship that occurs between certain tree roots and fungi since it has many ecological implications, such as the diversity and distribution of these species(Molina 1994). Whereas saprophytic fungi feed mostly on decaying wood and contribute to decomposing litter and nutrient cycling, ectomycorrizal fungi form mantles that cover the roots of certain trees and produce a complex network where nutrients are exchanged between the fungal hyphae and the roots, meaning that both species rely on each other for survival (Molina 1994).

Grey coral fungus (Clavulina coralloides)

Grey coral fungus (Clavulina coralloides)

Not all trees necessarily participate in this exchange and if they do, it is only with certain ectomycorrhizal fungi (Knudson 2012). This determines which forest types certain coral and tooth fungi will live in and how they will be distributed. For instance, as discussed in a recent paper on the Ramaria genus in Minnesota, ectomycorrhizas within this genus interact specifically with Abies (Fir), Cedrus (Cedar), Fagus (Beech), Larix (Larch), Picea (Spruce), Pinus (Pine) and Quercus (Oak) trees (Knudson 2012). A recent study also demonstrated that competition for root tips and soil resources between ectomycorrizal fungi has a direct influence on the structure and distribution of their community, however how these competitive interactions unfold is still not fully known (Kennedy 2010).


Knowing the ectomycorrhizal or saprophytic characteristics of our study species, we asked ourselves what is the distribution and diversity of coral and tooth fungi in the Morgan Arboretum. We hope this information can give us an idea of the tree diversity by looking at known ectomycorrhizal relationships as well as the amount of dead trees present in the ecosystem used by saprophytic fungi.

Our methods used during the lab periods all revolve around visual observation. We start by choosing three areas of the arboretum: a beech forest, a coniferous forest and a mixed deciduous forest. We go to different areas every lab so we do not observe the same fungus twice. We then spend twenty five minutes in each search area searching. By spreading out and walking in one direction, we manage to cover a lot of ground. Once a coral or tooth fungus is spotted, we stop our timer and regroup to identify it using field guides, measure it, note down its habitat and take a picture of the tree canopy. We take a picture of the tree canopy to be able to measure the amount of light through Photoshop by looking at the colour of pixels. To keep track of our observations, we use the application iNaturalist which has proven to be very helpful. We put in an equal amount of effort everywhere we search so our results are as accurate as possible.

Because of the limitations related to morphology-based observations, DNA analysis methods are now being used to gain a better understanding of the phylogenetic relationships between species. For instance, a recent study supports the theory according to which the coral-shape structure of the clavarioid fungi is the product of evolutionary convergence (Dentinger & David, 2006), thus that the species aren’t all closely related. The results of the experiment also suggest that some classifications would need to be reconsidered and that a new genus, Alloclavaria, should be created. After all, science is a never ending quest! Theories need to be constantly called into question and adapted. To keep track of what we are doing, follow us on twitter: MacShrooms (@MacFungiHunters)!

Dead coral mushroom

Dead coral mushroom


Dai, Yu-Cheng. “A Revised Checklist of Corticioid and Hydnoid Fungi in China for 2010.” Mycoscience 52.1 (2011): 69-79. Springer Link. Web. 25 Oct. 2013.

Dentinger, Bryn T. M.; McLaughlin, David J. “Reconstructing the Clavariaceae using nuclear large subunit rDNA sequences and a new genus segregated from Clavaria”. Mycologia. 17 Jul. 2006. Web. 25 October 2013.

Kennedy, Peter. “Ectomycorrhizal fungi and interspecific competition: species interactions, community structure, coexistence mechanisms, and future research directions.” New Phytologist 187.4 September 2010: 895-910. Science Direct. Web. 25 October 2013.

Knudson, Alicia Grace. “The Genus Ramaria in Minnesota.” Feb. 2012. Print.

Lepp, Heino. “Mycorrhizas.”Australian National Botanical Garden. 22 Jan. 2013. Web. 25 Oct. 2013

Molina, Randy. 1994. “The Role of Mycorrhizal Symbioses in the Health of Giant Redwoods and Other Forest Ecosystems” Gen. Tech. Rep. PSW-151. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 81 p. Web. 25 October 2013.

Ostry, Michael E.; Anderson, Neil A.; O’Brien, Joesph G. 2011. “Field guide to common macrofungi in eastern forests and their ecosystem functions.” Gen. Tech. Rep. NRS-79. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 82 p. Web. 25 October 2013.

Pickles, Brian J., David R. Genney, Ian C. Anderson and Ian J. Alexander. “Spatial analysis of ectomycorrhizal fungi reveals that root tip communities are structured by competitive interactions.” Molecular ecology 21.20 October 2012: 5110-5123. Science Direct. Web. 25 October 2013.

Puplett, Dan. “Mycorrhizas.” Trees for Life. Web. 25 October 2013.

Sicard, Mathieu.; Lamoureux, Yves. Les champignons sauvages du Québec. Anjou : Éditions Fides, 2005. Print.

Further Reading:








Natural history of White-tailed Deer

The Northern Woodland White-tailed Deer (Odocoileus virginianus ssp. borealis) is a species of deer found throughout Quebec, including the St. Lawrence Lowland region (Bernhardt et al. n.d.). Its name comes from the white underside of its tail, which can be seen when the deer is alarmed (Rue 2004).

Figure 1. The white-tailed deer’s trademark tail can be seen when the deer is alarmed. Photo courtesy of Sarah Stern, 2013.

Figure 1. The white-tailed deer’s trademark tail can be seen when the deer is alarmed. Photo courtesy of Sarah Stern, 2013.

Within the St. Lawrence region, white-tailed deer can be found in conifer and hardwood forests. These brown-coated mammals are crepuscular, which means that they are most active at dusk and dawn (Feldhamer and McShea 2012).

Figure 2. Infrared game camera captures a white-tailed deer in the Morgan arboretum. Photo courtesy of Munib Khanyari, 2013.

Figure 2. Infrared game camera captures a white-tailed deer in the Morgan arboretum. Photo courtesy of Munib Khanyari, 2013.

A white-tailed deer’s diet is primarily comprised of browse and forbs; however, because they are opportunistic, they have been known to eat birds and other small animals. Northern woodland white-tailed deer are among the largest of the subspecies, with adult bucks weighing about 100 kg and adult does weighing about 66 kg. Male deer have antlers that grow annually and are used to defend territory or fight over a potential mate (Geist 1998, cited in Innes 2013). Antlers may also be a secondary sexual trait; a study from 2000 found a link between antler development and pathogen resistance, suggesting that antler development may be a signal of male genetic quality (Ditchkoff et al. 2001). Baby deer, called fawns, are precocial, but they lack the muscle strength to outrun predators. Instead, they have white spots on their back and are almost odourless, which helps them camouflage with the background. As the fawn grows older and stronger, it will develop stronger scent glands and lose its spots, as it will be able to rely on speed to escape from predators (Feldhamer and McShea 2012).

Figure 3. Scent glands are found all over the deer’s body, and are used for communication with other deer (Rue, 2004)

Figure 3. Scent glands are found all over the deer’s body, and are used for communication with other deer (Rue, 2004)

White-tailed deer are not a migratory species; studies have shown that they usually stay within the same range (about one square mile) for most of their lives. In fact, “large numbers [of deer] have starved to death rather than leave a yarding spot to move even a few miles to an area where there may be abundant food” (Rue, 1962). However, their movement varies between summer and winter; the deer retreat to denser parts of the woods during winter to seek shelter. The daily activity of deer primarily consists of searching for food, but during “rutting” or mating season, bucks can be seen sparring with other bucks and marking his territory by rubbing his antlers on a tree and scraping the ground with his hooves (Rue 1962; Rue 2004).


Aging methods

Aging a deer has always been a difficult task. The most common technique is to look at the development and wear of its teeth. While this practice is widely used and accepted (Severinghaus 1949, cited in Gee et al. 2002), a study on 106 deer jawbone samples reveals that it may not be very accurate. The researchers were unable to assign a specific age to the jawbone samples, but categorized them into 3 basic age classes (fawn, yearling and adult). Thirty-four white-tailed deer biologists then attempted to age the jawbones, and failed 60% of the time for samples greater than two years of age. The results found the method of using tooth wear to indicate age very inaccurate beyond that of the 3 basic age classes (Gee et al. 2002).

Habitat preference and sexual segregation

In 2002, a team of researchers used data from forest maps and field surveys to investigate habitat preference and gender segregation of white-tailed deer. They hypothesized that does would seek out dense, sheltered forest during growing season to protect their fawns. The map analyses did not reveal gender segregation, but the field surveys showed that habitat preferences differed by gender. While both sexes used dense forest in the growing season, the males eventually spread out into more open spaces later in the season. The researchers concluded that aerial maps are not detailed enough to be indicative of habitat preference (Lesage et al. 2002).

Deer density based on aerial surveys and pellet-based distance sampling

In 2008 to 2009, a team of researchers compared aerial surveys and pellet-based distance sampling to estimate deer density in 6 preserved forests near Chicago, Illinois. They compared density estimates obtained from the use of both methods, as well as costs, bias, and precision. It was concluded that collecting accurate data on pellet decay and decomposition rates, using a large enough sample size, would be a more efficient and advantageous way of collecting density data than aerial surveys. Data from pellet samplings were less costly, required less equipment and professional skill, and did not depend on snow covering the ground. To conclude, the team discussed the importance of further research (Urbanek et al. 2012).

Figure 4. Fresh deer scat found in the Morgan arboretum, 2013.

Figure 4. Fresh deer scat found in the Morgan arboretum, 2013.

Depredation caused by deer diet

White-tailed deer have been known to cause extensive damage to field corn. Up to 80 to 90% of deer diets are comprised of corn, which causes the loss of millions of dollars each year. A research study from 2006 revealed that deer prefer certain corn hybrids based on nutrient content and time of maturity. The deer displayed a preference towards earlier maturing hybrids that contained higher levels of digestible material. Additionally, in a study from 2005, 67% of deer-feeding activity ensued in herbicide-treated areas rather than in untreated areas. As deer mostly feed on the edges of corn fields, farmers could reduce damage to their crops by planting hybrids undesired by deer on the edges of fields to minimize depredation (Delger et al. 2011).

Figure 5. Evidence of deer browse at Mcgill Dean’s Cornfield, October 2013

Figure 5. Evidence of deer browse at Mcgill Dean’s Cornfield, October 2013

Figure 6. Trampled vegetation around edges of McGill Dean’s Cornfield, 2013.

Figure 6. Trampled vegetation around edges of McGill Dean’s Cornfield, 2013.


White-tailed deer living in the Morgan Arboretum are constantly surrounded by humans and we want to know if deer activity is affected by human activity (agriculture, cultural services, urban development, etc.). To measure this, we are analysing deer signs (tracks, scats and browse) in relation to a scale of human activity.*

Figure 7. Identification of white-tailed deer tracks (Elbroch and Murie 2005).

Figure 7. Identification of white-tailed deer tracks (Elbroch and Murie 2005).

Figure 8. Hoof print of white-tailed deer at McGill Dean’s Cornfield, 2013.

Figure 8. Hoof print of white-tailed deer at McGill Dean’s Cornfield, 2013.

We set up three quadrants for each rank of the scale, for a total of 18 quadrants, throughout the Morgan Arboretum, the McGill bird observatory and the McGill Dean’s cornfields. Thus, our research question is redefined as follows: How do human disturbances (agriculture, cultural services, urban development, etc.) affect the activity of white-tailed deer in the Morgan Arboretum and its surrounding areas during the month of October?

We hypothesize that deer will generally avoid areas disturbed by humans, unless food resources are readily available. Deer activity should be most abundant within the denser forests (ranks 0-2), and scarcer within the areas of greater human disturbance (ranks 3-5). Rank 4 (agricultural area), however, may be an outlier as we hypothesize that this particular human disturbance (i.e. corn fields) will be a source of food for the deer and thus increase deer activity.

For data collection, the 10m x 10m quadrants are set up using measuring tape and marking tape. Within these quadrants, we search for deer signs, which we count and include in our data table. We also note the date, time and temperature of our session, as well as a brief description of the type of vegetation, fauna, soil etc. found inside the quadrant or nearby it. Any deer tracks are then erased to avoid replication of data. For the other two visits, we go back to the quadrants on a different day and search for fresh deer signs.

Video 1. How to set up a quadrant and collect data

*Scale of area studied in relation to human activity:

  • 0: Dense forest without human activity (Morgan arboretum)
  • 1: Light forest away from human activity (50m+) (Morgan arboretum)
  • 2: Forest seasonally used by humans (McGill bird observatory)
  • 3: Forest within visual distance (up to 30m) of regularly used paths (Morgan arboretum)
  • 4: Agricultural area (McGill Dean’s Cornfields)
  • 5: Area near/on roads, parking lots, buildings, etc. (Morgan arboretum)


Video 2. Vlog of quadrant 0.3 (Dense forest without human activity)

Video 3. Vlog of quadrant 1.1 (Light forest away from human activity)

Video 4. Vlog of quadrant 2.2 (Forest seasonally used by humans)

Video 5. Vlog of quadrant 3.2 (Forest within visual distance of paths)

Video 6. Vlog of quadrant 4.1 (Agricultural area)

Literature Citations

  1. Bernhardt T et al. n.d. The Canadian Biodiversity Website. The Redpath Museum [Internet]. Available from: http://canadianbiodiversity.mcgill.ca/english/species/mammals/mammalpages/odo_vir.htm
  2. Delger J, Monteith K, Schmitz L, Jenks J. 2011. Preference of white-tailed deer for corn hybrids and agricultural husbandry practices during the growing season. Human–Wildlife Interactions 5(1):32–46 [Internet]. Available from: http://www.berrymaninstitute.org/journal/spring2011/6__Delger.pdf
  3. Ditchkoff S, Lochmiller R, Masters R, Hoofer S, Van den Bussche R. 2001. Major-histocompatibility-complex-associated variation in secondary sexual traits of white-tailed deer (Odocoileus virginianus): evidence for good-genes advertisement. Evolution [Internet]. 55(3): 616-625; Available from: http://onlinelibrary.wiley.com.proxy1.library.mcgill.ca/doi/10.1111/j.0014-3820.2001.tb00794.x/pdf
  4. Elbroch M and Murie O. 2005. The Peterson field guide to animal tracks, 3rd ed. Singapore: Houghton Mifflin Company. p. 282-285.
  5. Feldhamer G and McShea W. 2012. Deer coat colors. In: Deer: the animal answer guide. Baltimore (MD): The John Hopkins University Press. p. 36-37, 92-93.
  6. Gee K, Holman J, Causey M, Rossi A, Armstrong J. 2002. Aging white-tailed deer by tooth replacement and wear: a critical evaluation of a time-honored technique. Wildlife Society Bulletin [Internet]. 30(2): 387-393; Available from: http://www.jstor.org/stable/3784495
  7. Geist V. 1998. White-tailed deer and mule deer. In: Deer of the world: Their evolution, behaviour, and ecology. Mechanicsburg (PA): Stackpole Books. p. 255-414.
  8. Innes R. 2013. Odocoileus virginianus. Fire Effects Information System [Internet]. Available from: http://www.fs.fed.us/database/feis/animals/mammal/odvi/all.html#131
  9. Lesage L, Crete M, Huot, J, and Ouellet J. 2002. Use of forest maps versus field surveys to measure summer habitat selection and sexual segregation in northern white-tailed deer. Canadian Journal of Zoology [Internet]. 80(4): 717-726. Available from: http://search.proquest.com/docview/220501969?accountid=12339
  10. Rue L. 1962. The world of white-tailed deer. Philadelphia (PA): B. Lippincott Company.
  11. Rue L. 2004. Varieties and distribution. In: The deer of North America. Guilford (CT): The Lyons Press. p. 25-26.
  12. Urbanek R, Nielsen C, Preuss T and Glowacki G. 2012. Comparison of aerial surveys and pellet-based distance sampling methods for estimating deer density. Wildlife Society Bulletin [Internet]. 36: 100–106. Available from: DOI: 10.1002/wsb.116

Beech Bark Disease in American Beech Trees (Fagus grandifolia)

Identification of an American beech tree (Fagus grandifolia):

Smooth bark of an American beech tree.

Smooth bark of an American beech tree.

Beech trees can be found in upland areas of a mature deciduous forest. The identification of a beech tree can be done year round with the use of five criteria appearing continually or seasonally:


Beech trees stand out by their thin, smooth, grey bark.


The leaves persist late into the winter. The single, oval leaves alternate along the twig with straight, feather-like arranged venation, with toothed margins. They also have a plastic-like texture.


There is a minimum of three bud scales per bud, overlapping one over the next. The buds are hairless, glossy, and smooth. They are stalkless and are attached directly to the base.

The nut and leaf of the American beech tree.

The nut and leaf of the American beech tree.


The flower opens typically in spring, along with leaf development.  The flowers are either male or female, with either single, inferior ovaries or a set of nine or more stamens. The flowers are arranged in a cluster, directly attached directly to the twig.


The fruit of beech trees develops into a nut, which is then surrounded by a spiny series of modified leaves (Fagus”, 2013).

American Beech Tree: Reproduction and Range

The American Beech tree has a range that extends from Nova Scotia, across Maine, southern Quebec, Ontario, Northern Michigan, and to far south parts of Texas and Florida. The American Beech is often a dominant or co-dominant tree species in its habitat.  Trees typically grow to between 20-25 metres and can live up to 300 years.  Beech trees reproduce both sexually and asexually.  In sexual reproduction, trees produce seeds when they are between 40-60 years old every 2 to 8. Fruiting occurs in September to October and seeds are released in October to November after frost.  Dispersal is limited and most seeds simply fall to the ground and are unviable if they have not germinated (in early spring to early summer) within a year (Coladonato, 1991).  In vegetative reproduction, new trees can sprout from stumps or suckers sent up from roots (Smallidge, 2009).

North American range of the Beech tree. (Image from http://en.wikipedia.org/wiki/File:Fagus_grandifolia_map.png)

North American range of the Beech tree. (Image from http://en.wikipedia.org/wiki/File:Fagus_grandifolia_map.png)

American Beech Tree: Beech Bark Disease

Beech Bark Disease (BBD) is a fast-spreading illness afflicting countless populations of beech trees (Randall, 2007). BBD is readily observable in the Morgan Aboretum.  BBD is the result of an insect-fungi complex that involves the Beech scale insect (Cryptococcus fagisuga), an invasive species introduced to eastern North America from Europe in the 19th century, as well as the Neonectria fungi (Neonectria faginata or N. galligena) (Houston and O’Brien, 1983). The scale pierces the bark in order to access the tree’s sap, enabling the fungi to infect the tree through these openings in the bark, leading to the creation of lesions and potential disruption of the tree’s nutrient and water transport process (Wieferich, 2011).  Consequently, these effects of infection can lead to leaf and bark loss, and eventually, to the death of the tree.  The scale reproduces rapidly in late summer and fall and is spread among Beech tree populations by wind mainly, but also by wildlife and human activities (Houston, 1994).

Left: Beech tree with Neonectria fungal colonization. Right: Beech tree with severe bark loss.

Left: Beech tree with Neonectria fungal colonization. Right: Beech tree with severe bark loss.

American Beech Tree: Uses & Importance

The American beech tree serves both ecological and economic significance. The flowering structures of this tree eventually develop into beechnuts, or beechmasts, which are a source of food for birds and various mammals, such as mice, squirrels, black bear, deer, etc (Coladonato, 1991). The wood of the beech tree is also exploited through the forestry industry, due to its sturdiness and resistance to decay (Gilman and Watson, 1993). Increasing mortality of the American beech tree due to Beech Bark Disease is an ecological concern since numerous species depend on these trees for food and shelter. A loss of American beeches would thus lead to a decline in wildlife habitat and food supply for a variety of species (“Wildlife”, 2013).

Beech Bark Disease: Research question

BBD team assessing the severity of disease in a younger beech tree.

BBD team assessing the severity of disease in a younger beech tree.

Our research has two main components: size and density of the beech tree.

Which factor, size or density, has a higher correlation with beech bark disease severity in the individual tree?

If we see a greater correlation between Beech Bark Disease and tree size, we can speculate that the disease is related to the age or development stage of the beech trees. By determining the density of the beech trees in our plots, we can then further investigate the spatial and tree-to-tree interactions of the disease.

Research methods:

To measure the density and tree size in relation to beech bark disease severity, we first chose four areas of study: two with majority beech populations and two with mixed beech and maple population. Within each of these areas, three random points were selected using GPS software. From each of these points, a 12m x 12m square plot was measured and the diameter at breast height was measured.

Measuring the diameter of the beech trees using diameter tapes.

Measuring the diameter of the beech trees using diameter tapes.

After each tree was measured, it was assessed for severity of beech bark disease. The severity was based on five characteristics: presence of scale, presence of cankers, presence of fungus, amount of bark loss, and amount of leaf loss. Each of these characters was then given a rating from 0-2, with zero being absent, 1 being low presence (<50%), and 2 being high presence (>=50%). These five ratings were then added together to give an overall disease scale from 0-10. By measuring the diameter and disease severity of every beech tree in a standard plot size, we were able to not only compare the severity of individual trees to their individual sizes, but also compare the average disease severity in each plot to the density as determined by the number of trees in the plot.

Beech Bark Disease: Severity Scale


Coladonato, Milo. “Index of Species Information: Fagus grandifolia.” Fire Effects Information System. USDA Forest Service, 1991. Web.

“Fagus grandifolia.” GoBotany. New England Wild Flower Society, n.d. Web. 19 Oct. 2013. <https://gobotany.newenglandwild.org/species/fagus/grandifolia/&gt;.

Gillman, Edward F. and Dennis G. Watson. “Fagus grandifolia: American Beech.” Fact Sheet ST-423. Florida: Insitute of Food and Agricultural Sciences, University of Florida, 1993. Web.

Houston, David R. and James T. O’Brien. “Beech Bark Disease.” Forest Insect and Disease Leaflet.  Washington: U.S. Department of Agriculture Forest Service, 1983. Web.

Houston, David R. “Major New Tree Disease Epidemics: Beech Bark Disease.” Annual Review of Phytopathology 32 (1994): 75-87. Web.

Randall, Morin S., Andrew M. Liebhold, Patrick C. Tobin, Kurt W. Gottschalk, and Eugene Luzader. “Spread of beech bark disease in the Eastern United States and its relationship to regional forest composition.” Canadian Journal of Forest Research 37.4 (2007): 726-736. Web.

Smallidge, Peter J. “Woodland Guidelines for the Control and Management of American Beech.” Forest Connect: Fact Sheet Series. ForestConnect.info. Department of Natural Resources, Cornell University Cooperative Extension, 2009. Web.

Wieferich, Daniel J., Deborah G. McCullough, Daniel B. Hayes, and Hancy J. Schwalm.  “Distribution of American Beech (Fagus grandifolia) and Beech Scale (Cryptococcus fagisuga Lind.) in Michigan from 2005 to 2009.” Northern Journal of Applied Forestry 28.4 (2011): 173-179. ProQuest. Web.

“Wildlife habitat.” Backyard Conservation Tip Sheet. Washington: U.S. Department of Agriculture, Natural Resources Conservation Service. Web. 19 Oct. 2013.


Distributions of earthworms in the Morgan Arboretum

Figure 1) Walking to our next St. Bernard soil location on a beautiful fall day at the Morgan Arboretum

Figure 1) Walking to our next St. Bernard soil location on a beautiful fall day at the Morgan Arboretum

With earthworms getting more attention as they make their way into once earthworm-free forests, it was surprising to find that there had been no past research done on the distribution of earthworms in the Morgan Arboretum. Due to the limited amount of time, we took this opportunity to target the St.Bernard soil series (one of the most common) as our research location. It is important to note that

for this natural history project, we will not be discriminating between specific species of earthworms but for earthworms as a whole. In a period of three field excursions, our goal is to answer the following research question: What is the earthworm distribution in the St. Bernard soil series of the Morgan Arboretum?


Three different locations of the St. Bernard soil series were selected to see if there was a difference in the distribution of earthworms. One location being beside a trail often used, one deeper in the forest, and the last on the edges of the agricultural field. A correlation between those specific locations and the presence of earthworms will be established, as well as a statement on the distribution of earthworms in the St. Bernard soil series of the arboretum.

To do so, a specific method is followed at each location on every lab session day. To locate the St. Bernard soil, a compilation of the soil series map and the arboretum map is used. As soon as we enter each location, an object is blindly thrown to identify the place where the first of three holes will be dug. To determine the location of the second hole, a team member spins around and points in a direction and walks 6 meters from the first hole. The third and last hole is situated at 6 meters from the second to make an equilateral triangle between the three holes. Blue tape is attached to a tree next to the first hole to ensure no repeats for the next lab session.

Figure 2) Compilation of the soil series map and satellite view of the Morgan Arboretum

Figure 2) Compilation of the soil series map and satellite view of the Morgan Arboretum

For each hole, we are limiting an area of about 1m2 to randomly take 10 measures of the height of leaf litter. After that, a hole of 30cm³ is dug. The soil is separated into two layers of 15cm each, and is put on two different plastic bags. The earthworms from each layer are put into a tray and counted. During this process, observations are made on moisture and the rocks in the soil. It is also important to note the temperature of the day and of the previous days to see if weather such as rain, had an effect on the distribution. This kind of research method is called the Handle Sample (Great Lakes Worm Watch 2011).

Figure 3) An equilateral triangle is formed when the 3 holes are connected

Figure 3) An equilateral triangle is formed when the 3 holes are connected

Figure 4) Fresh leaf litter on the forest floor

Figure 4) Fresh leaf litter on the forest floor

Figure 5) One of our sample points regardless of the amount of obstacles around it

Figure 5) One of our sample points regardless of the amount of obstacles around it

General information on earthworms

The behavior and anatomy of earthworms are indicative of how well adapted they are to living in soil. Earthworms excrete a fluid that lubricates their skin, making it easier for them to tunnel through the soil. Each segment on their body (except for the mouth and anus) has a pair of setae, hair like structures that anchor parts of their body during movement (typical feature of all oligochaetes). Earthworms have no eyes but are sensible enough to light to distinguish between day and night; this is helpful since most of their predators are diurnal and explains why they are most active at night (Darwin 1881).

Figure 6) A variety of different earthworms in terms of size

Figure 6) A variety of different earthworms in terms of size

Earthworm burrows are typically found near the topsoil, closest to their main sources of food: decaying organic matter and leaf litter. However, they are known to tunnel as deep as 2m during periods of dryness or in winter (Encyclopaedia Britannica 2013). Their digestive systems run through the entire length of their tube-like bodies. The food they eat is passed through their bodies and left in their burrows making the nutrients more readily available to plant life, thus accelerating the natural process of nutrient cycling (Encyclopaedia Britannica 2013).

Additional information: bbc.co.uk

Earthworms and the St. Bernard soils

St. Bernard soils have good drainage and are very stony due to their development on glacial till (Lajoie 1960). The A horizon is characterized as having a thick first layer of soil under a large accumulation of organic matter. The natural vegetation on this soil consist of sugar maples, yellow birch and beech trees which do not acidify the A horizon (Lajoie 1960). It is because of these reasons that invasive earthworm species would likely be found in the A horizon of St. Bernard soils.

Earthworms greatly affect the soil and the surrounding vegetation. Earthworms create tunnels in the soil, aerating it out and speeding up erosion and weathering (Wironen and Moore 2006).  Also, an increased number of earthworms can lead to an increased amount of carbon and nitrogen in the soil (Wironen and Moore 2006). Earthworms also contribute to the decomposition of organic matter at the surface of the soil and it is believed that this “may lead to changes in plant species” (Wironen and Moore 2006).

Additional information: soilsofcanada.ca

Figure 7) A burrow from an earthworm

Figure 7) A burrow from an earthworm

Figure 8) A clew of earthworms in the process of decomposing organic material

Figure 8) A clew of earthworms in the process of decomposing organic material

Earthworms as invasive species

The invasion of the European earthworm, Lumbricus terrestris to North America in the 1700s has many ecologists worried for the future of mixed deciduous-conifer trees of North America (Frelich et al. 2006). It may be hard to digest the fact that earthworms can be harmful in the soil due to their range of beneficial attributes to the home of gardens, but in a forest, these small soil engineers disrupt the ecosystem greatly. The thick carpet layer of leaf litter on forest floors has structured the soil underneath, such that bulk density is much lower than soil cultivated by humans (Frelich et al. 2006). With the earthworms slowly moving towards these forests, they increase the bulk density by aggregating soil particles together during decomposition. Thick leaf litters that have been accumulated over the years are also crucial in nutrient cycling and promotion of root growth for plant species (Frelich et al. 2006). For example, worm invasion in the sugar maple trees (Acer saccharum) has reduced the amount of tree seedlings and plant cover (Frelich et al. 2006). Seeds and seedlings are exposed once leaf litter is removed, leaving it more prone to freezing, predators and other organisms (Frelich et al. 2006). Such changes to the forest floor are bound to have a negative impact on plants that have adapted to thick forest floors. Although L. terrestris is a slow moving earthworm, its soil engineering impact is huge and must be carefully looked after for the future of North America’s forests (Frelich et al. 2006).

Additional information: invadingspecies.com, cleaveland.com, npr.org

Figure 9) The amount of earthworms gathered in one of our holes

Figure 9) The amount of earthworms gathered in one of our holes


Darwin C. 1881. The formation of vegetable mould, through the action of worms, with observations on their habits. First edition. London: Murray.

Encyclopaedia Britannica [Internet]. 2013. United Kingdom: Encyclopaedia Britannica; [updated 2013; cited 2013 Oct 24]. Available from: http://www.britannica.com/EBchecked/topic/176371/earthworm

Frelich LE, Hale CM, Scheu S, Holdsworth AR, Heneghan L, Bohlen PJ, Reich PB. 2006. Earthworm invasion into previously earthworm-free temperate and boreal forests. Biological Invasions. 8(6): 1235-1245. DOI: 10.1007/s10530-006-9019-3

Great Lakes Worm Watch [Internet]. 1999-2011. Duluth, Minnesota: University of Minnesota; [updated 2011; cited 2013 Oct 24]. Available from: http://www.nrri.umn.edu/worms/research/methods_worms.html

Lajoie PG. 1960. Soil Survey of Argenteuil, Two Mountains and Terrebonne Counties, Quebec. Ottawa: Research Branch, Canada Dept. of Agriculture.

Wironen M, Moore TR. 2006. Exotic earthworm invasion increases soil carbon and nitrogen in an old-growth forest in southern Quebec. Canadian Journal of Forest Research. 36: 845–854.  DOI:10.1139/X06-016


Medicinal Plants

Medicinal plants have been used to treat an array of illnesses dating back thousands of years. It is not known exactly who discovered that plants have medicinal properties, but scriptures describing their uses, written around 3000 B.C. by the Egyptians and Ancient Chinese, have been discovered (Ehrlich 2013). Researchers have shown that, throughout time, indigenous cultures from various parts of the world have used the same or similar plants for treating the same afflictions in their traditional rituals and therapies (Ehrlich 2013). However as scientists began to develop synthetic drugs mimicking a medicinal plant’s properties, the use of natural remedies declined until recently, as many people are deciding the natural way is healthier (Ehrlich 2013). Though the use of natural remedies is increasing, many people buy them from a store instead of going outside and finding the plant itself. This can be due to the fact that many medicinal plants can be poisonous when consumed in large quantities, but typically it is because people do not know how to identify them or where to look for them; not realizing the plant could be growing in their backyard.

There are many commonly found medicinal plants all over Canada, such as Hypericum perforatum (St John’s wort), Plantago major (common plantain) and Asteraceae (dandelion). Due to the time of year and location in which our research project takes place, the study plants must be able to survive late into an Eastern Canadian autumn, which influenced our decision to study 5 perennial and 1 biennial species we knew to be located within the Morgan Arboretum. These species either preferred to live on moist shady soils (Arisaema triphyllum, Asarum canadense,Smilacina racemosa, Polygonatum) or near woodland edges in either part shade or full sun (Artcium minus, Sanguinaria canadensis) (PFAF 1996-2012). By choosing species that typically have similar habitats we anticipated being able to locate them all in the area bordered by the orange trail and within the amount of time available to us.

Overview of Study Species

Arisaema triphyllum (Jack in the pulpit)

Female Arisaema triphyllum

Female Arisaema triphyllum

Description: Grows a spadix encased in a spathe that opens up at the top like a hood. In late summer, mature plants produce a cluster of red berries that become visible as the spathe withers. The sex of individuals is determined by their life stage: juvenile is male, mature is female, and intermediate is often a hermaphrodite (Bierzychudek 1982).

Medicinal properties: Ariseama triphyllum’s root is used as a stimulant and antiseptic substance, and to clear chest phlegm and induce perspiration. If the root is not properly dried, it is poisonous to humans once ingested (PFAF 1996-2012). First nations used roots in decoctions and applied them to bruises, sores, and sore heal throats.

The Arisaema triphyllum that we found along our transects were female, easily discernible from the earlier male stage by its bright red berries, making it easy for us to spot. They grow as single plants; however we often found two or three in close proximity to each other.

Arctimum minus (Common Burdock)

Cluster of Arctimum minus

Cluster of Arctimum minus

Description: A biennial herb, introduced from Europe, which grows with rosettes comprising of broad leaves and purple flowers on a long stalk (Gross and Werner 1983).

Medicinal properties: Infusions of its leaves, used for centuries, cure ulcers and various skin infections. This plant helps purify the blood, kill bacteria and fungi, expel intestinal gases, promote bile and urine flows, and reduce blood sugar levels (PFAF 1996-2012). Boiling the root creates a good antidote for food poisoning.

As fall takes over Arctimum minus begins its seed dispersal and the shoot dies in preparation for winter. It is found in clusters all along edges of paths and clearings.

Caulophyllum thalictroides (Blue Cohosh)

Caulophyllum thalictroides with berries still intact

Caulophyllum thalictroides with berries still intact

Description: A perennial herb composed of a single straight stem and a single leaf bearing three leaflets. At maturity, it is recognized by its blue berry-like seeds surmounting its stalks (Brett and Posluszny 1982).

Medicinal properties: An important North American medicine for its many gynecological uses, promoting urination, menstruation and relaxing muscular spasms and cramps. Native Americans used it to relieve menstrual cramps and to promote childbirth (Betz et al. 1998). The berry-like fruits are poisonous.

They have already browned at this time of year and though they resemble mere twigs they manage to hold onto their blue seeds with strength that astounds us, surviving some harsh winds and heavy rain—partially weakened by the tree canopy. They are found scattered around the forest in groups.

Sanguinaria canadensis (Bloodroot)

Sanguinaria canadensis: (L) leaves (C) root (R) yellowing leaves

Sanguinaria canadensis: (L) leaves (C) root (R) yellowing leaves

Description: An herbaceous perennial, native to North America. Composed of 3 stems each bearing a single basal leaf arranged in palmate lobes (Agriculture and Agri-Food Canada). As its common name suggest, the root produces a reddish juice, which has been used to make dyes. In early spring, white flowers will bloom and before winter the leaves yellow and die. The root remains red.

Medicinal properties: The red sap is not poisonous in low doses and was extensively used by First Nations for its antimicrobial and anti-inflammatory properties. It can cure poison ivy, promote urine and menstrual blood flows, vomiting and is used to reduce fever or clear phlegm by inducing coughing. It is also used as a stimulant and a sedative (PFAF 1996-2012). It has been used in commercial toothpastes to fight gingivitis but was withdrawn after problems with sores in some patients.

Smilacina racemosa (False Solomon’s Seal) vs. Polygonatum (Solomon’s Seal)

(L) Smilacina racemosa leaves and (C) S. racemosa with beries. Compare to (R) Polygonatum sp.

(L) Smilacina racemosa leaves and (C) S. racemosa with beries. Compare to (R) Polygonatum sp.

Descriptions: Perennial herbs often found in dense clusters in rich woods. Smilacina racemosa is often confused with a Polygonatum as the leaves on both plants are arranged in a similar fashion, with smooth edges and elliptical shapes. The main difference is that Smilacina racemosa develops flowers and small red berries at its tip, while Polygonatum develops them on its underside.

Medicinal use: Smilacina racemosa is a contraceptive and regulates menstruation. The root is analgesic and antirheumatic. When burned, the fumes can heal headaches and body pain. Not commonly used in modern medicine (PFAF 1996-2012). Polygonatum is used for spitting up blood and for treating snow blindness (PFAF 1996-2012).

Project Overview:

Our research question, where in the Arboretum are the chosen medicinal plants found, does this correlate with a specific habitat?, stems from our interest in finding a relationship between the plants and their surroundings; potentially coming up with a map of the areas in the Arboretum likely to contain medicinal plants.

To have a realistic sized research area the orange path of the Morgan Arboretum was chosen as the boundary. We ran eight transects, separated from each other by 70 paces (1 pace = roughly 1 meter). One group member was responsible to maintain our trajectory as straight as possible from one side of the main path to the other by use of a compass and a GPS. The other three members followed scanning the ground for the study species within a 2 m distance of either side of our transect. Each time a study species was found along a transect, its GPS coordinate was taken, along with environmental conditions, and were recorded on a data sheet (figure 1). After transects are completed, the soil type on which each plant discovered, will be determined by reference of a Morgan Arboretum soil survey map.

Data Collection Table

Data Collection Table


Agriculture and Agri-Food Canada. Sanguinaria canadensis L. (Bloodroot) [Internet]. 2012; [cited on 2013 October 27]. Available from: http://www.agr.gc.ca/eng/science-and-innovation/science-publications-and-resources/resources/canadian-medicinal-crops/medicinal-crops/sanguinaria-canadensis-l-bloodroot/?id=1301435750051

Betz JM, Andrzejewski D, Troy A, Casey RE, Obermeyer WR, Page SW, Woldemariam TZ. (1998). Gas Chromatographic Determination of Toxic Quinolizidine Alkaloids in Blue Cohosh Caulophyllum thalictroides (L.) Michx. Phytochemical Analysis [Internet]. [cited 2013 October 25]; 9(5): 232-236. Available from: http://onlinelibrary.wiley.com.proxy2.library.mcgill.ca/doi/10.1002/%28SICI%291099-1565%28199809/10%299:5%3C232::AID-PCA412%3E3.0.CO;2-5/abstract;jsessionid=F4AA3511F27C4CDC0584CB738111DD7F.f02t02

Bierzychudek P. 1982.  The demography of Jack-in-the-pulpit, a forest perennial that changes sex. Ecological Monographs. 52(4): 335-351

Brett JF, Posluszny U. 1982. Floral development in Caulophyllum thalictroides (Berberidaceae). Canadian Journal of Botany [Internet]. [cited 2013 October 27]; 60(10): 2133-2141. Available from: http://www.nrcresearchpress.com/doi/abs/10.1139/b82-262#.Um3NZyRie8o

Ehrlich SD. Herbal Medicine. University of Maryland Medical center .  [internet]  2013; [cited on 2013-10-24]. Available from: http://umm.edu/health/medical/altmed/treatment/herbal-medicine

Gross RS, Werner PA. (1983). Probabilities of Survival and Reproduction Relative to Rosette Size in the Common Burdock (Arctium minus: Compositae). American Midland Naturalist [Internet]. [cited 2013 October 25]; 109(1): 184-193. Available from: http://www.jstor.org.proxy2.library.mcgill.ca/stable/2425529

MacKinnon, Kershaw, Arnason, Owen, Karst, Hamersley-Chambers. 2009. Edible and medicinal plants of Canada. Lone Pine

Plants for a Future (PFAF) Arisema triphyllum [Internet]. 1996-2012; [cited on 2013-10-27]. Available from: http://www.pfaf.org/user/Plant.aspx?LatinName=Arisaema+triphyllum

Plants for a Future (PFAF) Polygonatum pubescens [Internet]. 1996-2012; [cited on 2013-10-27]. Available from: http://www.pfaf.org/user/Plant.aspx?LatinName=Polygonatum+pubescens

Plants for a Future (PFAF) Smilacina racemosa [Internet]. 1996-2012; [cited on 2013-10-27]. Available from: http://www.pfaf.org/user/Plant.aspx?LatinName=Smilacina+racemosa


Winter adaptations of the Black-Capped Chickadee in the St-Lawrence Lowlands

The Black-Capped Chickadee (Poecile atricapillus) perched on bird feeding house at Research Site #1

The Black-Capped Chickadee (Poecile atricapillus) perched on bird feeding house at Research Site #1

Black-capped Chickadees, Poecile atricapillus, are year round songbirds native to North America.3 Their habitat ranges from the Maritimes up to Alaska, covering 2/3 of Northern and Central United States.3,4. Living in flocks of four to twelve birds, Chickadees can be seen in different habitats such as orchards, deciduous and coniferous woodlands, cotton wood groves, parks and other wooded areas.2,3,4 They may also be found near the edges of forests.2 These habitats provide nesting sites as well as food.2 By the end of March, “1-2 weeks before egg laying”2, female Chickadees build their nests in abandoned cavities excavated by woodpeckers or other natural cavities.1 Females might also, with the help of males, excavate their own cavities in the rotting wood of stumps1,3  Here, female Chickadees lay seven eggs per season on average.4

Tree cavities near Research Site #1, a prime location for black-capped chickadees to roost and sleep

Tree cavities near Research Site #1, a prime location for black-capped chickadees to roost and sleep

During the breeding season, Chickadees forage mainly for caterpillars, as well as fruits and seeds.2  During the winter, their diet primarily consists of insects, spiders, berries and seeds.2 Chickadees may be observed feeding at birdfeeders, or even on animal carcasses.1,4 Although these birds are notoriously bold and audacious for their size, they are vulnerable to predators such as owls, small hawks and shrikes.4 Chickadees make sharp “zeet” calls to alert others to the presence of predators.4 On average, they have fifteen different calls for different purposes, including the well-known “chickadee-dee-dee” call which inspired the bird’s name.3

(Video: Vocalizations of Black-Capped Chickadees at Research Site #2)

Black-capped Chickadees change their feeding and territorial behaviours over time in order to survive cold winter conditions.8 They are known to alter their vocalization, flocking behaviour, breeding territories, food sources and caching storages over the year.7 Chickadees have physiological and ecological adaptations for winter survival such as nocturnal hypothermia, the reduction of their body temperature over night; thermogenesis, shivering to produce heat; over-wintering in heterospecific bird flocks, commonly with woodpeckers and nuthatches; foraging at lower heights for increased wind protection, and caching, storing food in autumn for later consumption during the winter.8

During the fall, Black-capped Chickadees can be observed eating at bird feeders -especially those with black sunflower seeds- and also frequently caching seeds, usually those of coniferous trees. Chickadees can fly upside-down and belly-up in order to extract seeds from branches and cones using their claws and beaks. According to Barbra Frei5 of the McGill Bird Observatory (MBO), Chickadees must eat about 10-15 percent of their body weight during the day to preserve enough energy to last the night. Chickadees fluff up their feathers while shivering in order to stay warm. They also travel in pairs or in small flocks to the feeders and from tree to tree.

A Chickadee preparing to take flight with a black conifer seed in its beak demonstrating caching behavior

A Chickadee preparing to take flight with a black conifer seed in its beak demonstrating caching behavior

A Chickadee breaking open a seed demonstrating feeding behavior

A Chickadee breaking open a seed demonstrating feeding behavior

(Video: Caching and Feeding Behavior of Black-Capped Chickadees at Research Site #1)

The specific focus of this project is on the behavior of Black-capped Chickadees, and how it changes with the approach of winter. To measure this, we constructed a data sheet with observable behaviors including feeding, foraging and caching as well as physiological adaptations such as shivering. Our aim is to observe the change in behavior and frequency of Chickadee activity at each research site over time. Our own eyes and ears have proven to be our most valuable tools, but technology such as a GPS device has enabled us to pinpoint the exact location of each research site and measure their approximate areas.

The three sites are all near the Orange Trail, a 3 kilometer loop in the Morgan Arboretum. Site one is a fairly open area of planted trees (including some exotic species) with a bird feeder and a high frequency of Black-capped Chickadee activity. Site two is between two rows of trees, allowing us to observe activity in a forest edge environment. Site three is in a mostly-coniferous and denser part of the Arboretum, with a high canopy. All sites include conifer trees, a major food source. Our procedure has been to split up into two groups of two, which start the loop in opposite directions in order to gather two sets of data (20 minutes per site) for each study site on each day.

Research Site #1 (bird feeding house not shown)

Research Site #1 (bird feeding house not shown)

Research Site #2

Research Site #2

We have collected data over the month of October, going to the Arboretum twice a week in the morning, once from 8am to 10am and once from 10am to 12pm. This allows us to observe differences in Chickadee behavior over the course of the morning, as temperature rises. The Black-capped Chickadee’s food caching begins in September and ends in February.7 Research site one has shown constant caching behavior from Chickadees as couples regularly come to the feeder to pick up seeds, then fly away within half a km to visibly peck at bark or lichen to store them. Other Chickadees who are visibly feeding by picking up a seed, breaking and instantly consuming it are fattening up either to facilitate nocturnal hypothermia or prepare for partial migration.

As the temperature and hours of sunlight decrease over the fall season, the Black-capped Chickadee must undergo observable physiological behavior such as shivering (thermogenesis) in order to survive, as there is only 2cm between the harsh winter conditions and their body cores.8 Thermogenesis can be identified by a change in posture and erection of the feathers as an initial response to colder temperature.8 As the season progresses, the Chickadees’ shivering bursts increase in frequency, mean duration, and magnitude.8

The social and hierarchical behaviour of Black-capped Chickadees does not observably change during the fall. The only Chickadees who are not associated with a flock or paired up with a mate are those which have hatched this year. These juveniles are smaller and are observed to undergo more feeding behavior than caching, indicating they are having the hardest time adapting to winter conditions. Black-capped Chickadees must increase their efficiency of energy use and storage to survive harsh winter nights8, and we have observed multiple flocks of Chickadees roosting in tree cavities close to plentiful food supplies of conifer seeds near research sites one and two, significantly lowering travel time and distance from their foraging areas.

(Video: Phishing Behavioural Response of Black-Capped Chickadees)


  1. The Cornell Lab of Ornithology. (n.d.). All about birds: Black-capped chickadee. Retrieved from http://www.allaboutbirds.org/guide/black-capped_chickadee/lifehistory
  2. Smith, S. M. (2010). The birds of north America: Black-capped chickadee. Retrieved from http://bna.birds.cornell.edu/bna/species/039/articles/behavior
  3. Lawrence, L. K. (2003). Hinterland who’s who: Black-capped chickadee. Retrieved from http://www.hww.ca/en/species/birds/chickadee.html
  4. Roof, J. (2002). Parus atricapillus: Black-capped chickadee. Retrieved from http://animaldiversity.ummz.umich.edu/accounts/Parus_atricapillus/
  5. Barbra Frei, Masters in Ornithology at McGill University and member of the staff at the McGill Bird Observatory bird banding station in Sainte-Anne de Bellevue.
  6. Munib and Yifu from the ENVB-222 course with Chris Buddle studying Chickadees in fall 2012.
  7. Otter, K. A. 2007. The Ecology and behaviour of Chickadees and Titmice; An integrated approach. Oxford Ornithology. Oxford University Press. United States. pp. 43-52
  8. Otter, K. A. 2007. The Ecology and behaviour of Chickadees and Titmice; An integrated approach. Oxford Ornithology. Oxford University Press. United States. pp. 265-274


Does location within the forest affect leaf colour change in Sugar Maple (Acer saccharum)?

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Acer saccharum, commonly known as the Sugar Maple, is a deciduous tree native to North America. Its genus ‘’acer’’ is latin for maple, and its species name ‘’saccharum’’ comes from the Greek word “sakcaron” meaning ‘’sweet juice distilled from bamboo’’ or simply ‘’sugar’’. (Acer saccharum 2013). This tree is probably most well known because its leaf appears on our national flag (The life of sugar maple 2013).

Sugar maples can grow up to about 25-35 meters in height . Their lifespan can be anywhere from 200 to 400 years , which is very impressive by our standards. The leaves are simple opposite, and can grow from 7 to 20 cm long.They are composed of 5 lobes that are separated by U-shape sinus, meaning the dips between the tips are rounded, not pointed. The leaves are a yellow-green to green colour during the summer and in fall, they can turn yellow, orange or red . The twigs are reddish-brown colour and have small openings on the surface of the bark . The monoecious flowers are greenish to yellowish and form in clusters on long stalks. The bark of the tree is light to dark gray. When the tree is young, the bark is smooth but with age it becomes scaly. The tree produces a fruit called samara that is about 30-35 mm long (Ontario 2013, The life of sugar maple 2013,Maple Sugar 2013,Sugar Maple 2013, Acer saccharum 2013,Arboreal Emblem 2013).

The tree is common in the Northeastern North America. It can be found in most Canadian provinces and in Northern States of the United States (Ontario 2013,The life of a Sugar Maple tree 2013). This tree prefers to live in moist, rich soil with plenty of sunlight although it can tolerate shade (Ontario 2013,The life of sugar maple 2013,Maple Sugar 2013, Acer saccharum 2013).

There are 10 other species of maple tree in Canada (Arboreal Emblem 2013), however the most economically important is the sugar maple for two reasons: maple syrup and timber. Maple syrup has been discovered a long time ago by the Native Americans and is now used widely in the food industry as a sugar source. The sugar maple is important for timber because it is strong, hard, and durable wood for making furniture, floors, paneling, etc (Acer saccharum 2013).

Sugar maple is an important component of an ecosystem. Animals such as white-tailed deer, moose, snowshoe hare, red squirrel, gray squirrel and flying squirrel feed on seeds, buds, twigs and leaves of this tree. Birds are known to nest in them as well (Acer saccharum 2013).

Why study this species?
As we can see, this species is economically and ecologically vital to us here in Quebec. Studying this species and learning more about it will allow us to better protect it. This is the reason why our team decided to study this species. Few studies have been made to explain the variations in leaf coloration. Lee & al. 2003 conducted a study to evaluate the dynamics of different pigments in the leaf, while Taylor & al. 2007 and Norby & al. 2000 talks about the effect of carbon dioxide and nitrogen on leaf senescence.

Photo credit: Julie Hamel

Photo credit: Julie Hamel

Description of our project
The objective of our research project is to track the change in the colour of the leaves in Sugar Maples (Acer saccarum). Our collected data includes the GPS coordinates of each tree, for identifying them week to week; the diameter of each tree, for a rough estimation of the age of the tree and an estimation of the percentages of the leaf colour. The way we make our estimations is by standing at the base of a tree, looking at the assemblage of leaves and cooperatively agreeing on their colour proportions i.e. 40% green, 50% yellow, 10% brown. We understand that this is not the most objective way of judging the colour but since many of them are continually falling and there can be hundreds to count it makes sense to take a estimate. The fact that we are 4 headstrong youths means that we have active debate over the proportions of the colours and always come to a consensus. The coordinates are taken with a digital GPS device and recorded in order to not mix up trees since the forest is not planted in uniform rows. The diameter is determined by simply measuring the circumference with a measuring tape and using the rule D=C/2pi where D=diameter and C=circumference. We used the transect method to chose which trees we would track. This means all the trees form 2 rough lines parallel to the edge of the forest, one about 10 metres from the nearest clearing and another 45 metres deeper into the forest. We have 2 sets of these 2 rows in different parts of the Morgan Arboretum meaning the total number of rows of trees in 4 and all 4 rows are about 100 metres in length.

Photo credit : Aurore Hernandez

Photo credit : Aurore Hernandez

We want to compare data from trees located on the edge of the forest with trees that are deeper inside the forest because the light exposure is different. The trees growing on the edge of the forest probably receive a higher amount of light than the trees growing inside the forest, which, as is usually the case, only have an upper layer of leaves exposed to sunlight. Since the recession of chlorophyll tends to be accelerated by environmental conditions such as bright sunlight and shorter day length (Coder 2008), our main goal is to observe the rate at which leaves from the edge/interior of the forest lose their green chlorophyll pigments. We will do so by making graphs comparing data from four different locations of the Morgan Arboretum collected on a weekly basis during a three week study period. Also, the same environmental factors that stimulate the loss of chlorophyll in leaves are known to increase the amount of carotenoids and generate the production of anthocyanins. (Coder 2008) Carotenoids are pigments distinguishable by their yellow and orange color and become noticeable when the chlorophyll starts to decrease. They give leaves a yellowish-green color. Anthocyanins are pigments that are generated due to environmental changes during Fall and are responsible for the red color in autumnal leaves.

Of course the rate of the chlorophyll breakdown in deciduous tree leaves is induced by several other changes in the environment such as moisture and the drop in temperature (Archetti & al 2013). We assume, under our research, that these factors affect all the sugar maples equally since they are all in close proximity to each other. It is also important to know that anthocyanins can be produced in the sugar maple leaves under various conditions where the leaves are weakened such as in the cases of deficiencies, wounding, pathogenic infections and ozone exposure. (Schaberg et al. 2008) A leaf’s quantity of red pigments depends on many factors other than the light exposition which is why we will focus on the withdrawal of the green color instead of on the apparition of the various, photogenic colors that the fall season is so well known for.


(1) Ontario, Ministry of Natural Resources [Internet]. 2013. Ontario: Ministry of Natural Resources. [July 16th 2013; October 27th 2013]. Available from: http://www.mnr.gov.on.ca/en/Business/ClimateChange/2ColumnSubPage/267334.html

(2) The life of a Sugar Maple tree [Internet]. 2013. United States: Cornell University; [October 27th 2013]. Avaible from: http://maple.dnr.cornell.edu/pubs/trees.htm

(3) Sugar Maple [Internet]. 2013. United States : Cornell University; [October 27th 2013]. Available from: http://maple.dnr.cornell.edu/kids/tree_sug.htm

(4) Arboreal emblems [Internet]. 2013. Canada: Canadian Forestry Association; [October 27th 2013]. Available from: http://www.canadianforestry.com/html/forest/arboreal_emblems_e.html

(5) Maple Sugar [Internet]. 2013. United States: Arbor Day Foundation; [October 27th 2013]. Available from: http://www2.arborday.org/treeguide/treeDetail.cfm?ID=14

(6) Acer saccharum [Internet]. 2013. United States: Rook; [March 4th 2006, October 27th 2013]. Available from: http://www.rook.org/earl/bwca/nature/trees/acersac.html

Scientific articles:

(1)  Coder KD. 2008. Autumn Leaf Colors. Warnell School of Forestry and Natural Ressources. 1-7.

(2) Schaberg PG, Murakami EPF, Turner EMR, Heitz HK, Hawley EGJ. 2008. Association of red coloration with senescence of sugar maple leaves in autumn. NRS.1-6.

(3)  Archetti M, Richardson AD, O’Keefe J, Delpierre N. 2013. Predicting Climate Change Impacts on the Amount and Duration of Autumn Colors in New England Forest.PLOS ONE. 8(3): 1-8.

(4)  Norby R, Long TM, Hartz-Rubin JS, O’Neilli EG. 2000. Nitrogen resorption in senescing tree leaves in a warmer, CO2-enriched atmosephere. Plant and Soil. 224:15-29.

(5)  Taylor G, Tallis MJ, Giardina CP, Percy KE, Miglietta F, Gupta P, Gioli B, Calfapietra C, Kubiske M, Scarasciamugnozza GE, Kets K, Long SP, Karnosky. 2007. Future atmospheric CO2 leads to delayed autumnal senescence. Global Change Biology. 14:1-12.

(6)  Lee DW, O’Keefe J, Holbrook M, Feild TS. 2003. Pigment dynamics and autumn leaf senescence in a New England deciduous forest, eastern USA. Ecological Research. 18:677-694.


Woodpecker Damage on Ash Trees at the Morgan Arboretum


The emerald ash borer (EAB) has killed 75 million ash trees in North America since 2002 (“Ville de Montreal”, 2015), causing Montreal to invest 15 million dollars over the next three years to deal with the infestation, and plant new trees (Laframboise, 2016). Predators of the EAB larvae include woodpeckers (Jennings et al., 2013). As the Island of Montreal is home to multiple species of both ashes and woodpeckers, we wanted to explore the relationship between these two organisms.

Emerald Ash Borer

The emerald ash borer is an invasive species to North America accidentally brought in from Asia (Daniel & Deborah, 2013). This green beetle feeds on the sap of ash trees and lays its eggs into the tree bark crevices. It infects all ash species (Daniel & Deborah, 2013). Damaged tree stands die within 1-4 years after infestation from this pest (“Emerald ash borer”, n.d). Since the EAB has no effective predator, forests with a high number of ash trees are likely to decrease significantly in the coming years.

image-1-and-2Figure 1. Ash tree leaves on the left and ash tree bark on the right.

Ash Trees

Ash trees (Fraxinus species) are large deciduous trees that grow on moist, well-drained soil in areas with direct sunlight. They have both opposite branching and leaves, and typically have 5-9 leaflets on a branch with smooth or toothed margins (Brown-Rytlewski & Thompson, 2003). They also produce wind dispersed samaras. Ash trees are easily identified by their bark; young trees have a relatively smooth, grey bark, whereas as they mature, diamond-shaped ridges develop.

Ash trees are common in many parts of the United States and Canada. On the island of Montreal ash trees are ranked the second most numerous species, with red ash being the most common (Rocha, 2015).

image-3Figure 2. Most common species of tree in Montreal based on boroughs.

White ash trees are the predominant species of ash present in our study area, the Morgan Arboretum, a forest reserve located on the western tip of the Island of Montreal.


Woodpeckers peck at tree trunks for numerous reasons, including finding insects and building nest holes. They drum into trees to communicate, and can tap up to 8,000-12,000 times a day (Eberhardt, 1997). Woodpeckers are found in wooded areas worldwide with the exception of Australia (Helmut, 2016). They have a diversified diet with insects as their primary food source, followed by fruits, seeds, and nuts. Their bodies are designed to prevent damage to vital organs; they have powerful neck muscles and a thick skull that protects their brain and spinal cord (Spring L. W., 1965).  The woodpecker’s tongue can extend, and is often covered with sticky saliva that allows them to catch more prey. They also have a strong, slightly curved bill that facilitates exposing insects in the tree bark (Zhou et al., 2009). At the Morgan Arboretum we observed damage on ash trees from the following woodpecker species: pileated, red-bellied, sapsucker, hairy and downy. Woodpecker characteristics vary, as shown in table 1.

table-1Table 1: Characteristics of Woodpeckers Observed at the Morgan Arboretum

Factors Influencing Woodpecker Foraging Activity

Forest type, tree density and tree health each influence woodpecker activity in different respects. In fact, it has been shown that a larger diversity of woodpecker species can be found in deciduous forests than in coniferous forests (Myczko et al., 2014). Moreover, low density forests are possibly preferable for larger woodpecker species, because they lead to less hampering of movement and foraging (Myczko et al., 2014). However, the forest density also affects smaller species of woodpeckers, such as sapsuckers.  According to Lawler & Edwards (2006), sapsuckers are more likely to nest in forests of low density. That study also showed that more sapsucker nests were observed in areas with a higher presence of fallen dead trees. This preference has also been shown for downy, hairy and red-bellied woodpeckers (Lindell et al., 2008). These results confirm that tree health is a factor affecting woodpecker activity. In a study by Flower et al., it was found that in EAB infested forests, bark-foraging birds, including woodpeckers, fed more often on ash trees, and preferentially fed on ash trees with canopy decline most likely linked to the EAB (Flower et al., 2014). No research addressing the relationship between woodpecker presence and ash tree bark quality has been conducted in the Arboretum.

Our Research

EAB invasion is likely to reduce ash tree populations in the coming years. We wanted to understand the relationship between woodpeckers and ash trees before ash tree populations decrease significantly. Research by Myczko et al. (2014), and Lawler & Edwards (2006) shows that tree density influences woodpecker presence, hence we incorporated basal area as a measure of tree density into our research. We also decided to measure density of ash trees more specifically since they are affected by the EAB.

Research question: Does the density of ash trees and basal area affect the foraging activity of woodpeckers on ash trees at the Morgan Arboretum?


To carry out our experiment, we randomly selected six 50m2 sectors, and divided them each into four 25m2 plots. Two out of the four squares were randomly selected. In each plot, we measured the diameter of all standing trees at breast height (DBH) and also identified the specie of each tree, to be able to calculate basal area. Furthermore, for all of the ash trees we encountered, we used iNaturalist to record the position and number of each tree, as well as photograph the woodpecker damage whenever it was encountered. Finally, each ash tree was ranked on two scales; one based on their bark quality, and the other based on the severity of the woodpecker damage on the tree.

table-2Table 2: Scale for Bark Quality  

table-3Table 3: Scale for Woodpecker Damage

Whenever possible, we noted the most probable woodpecker species, that had caused the damage observed on the tree. The data collected will be analyzed in order to see if there is any correlation between ash tree density, basal area and woodpecker damage in the Arboretum.

Here is a video describing our data collection process.



Ash tree identification guide. Retrieved October 24, 2016, from TreeRemoval.com, http://www.treeremoval.com/ash-tree-identification-guide/#.WA7RC5MrJE4

Brown-Rytlewski, D., & Thompson, R. (2003, May). Distinguishing Ash from other Common Trees. Retrieved from http://www.emeraldashborer.info/documents/E-2892Ash1.pdf. doi: 10.1146/annurev-ento-011613-162051

Bunn, B. Northern flicker. Retrieved October 25, 2016, from https://www.allaboutbirds.org/guide/Northern_Flicker/lifehistory

Daniel, A. H., & Deborah, G. M. (2013, October). Emerald Ash Borer Invasion of North America: History, Biology, Ecology, Impacts, and Management. Retrieved from (1) https://www.colorado.gov/pacific/sites/default/files/atoms/files/Emerald%20Ash%20Borer%20Invasion%20of%20North%20America.pdf

Eberhardt, L. S. (1997). A test of an environmental advertisement hypothesis for the function of drumming in Yellow-Bellied Sapsuckers. The Condor, 99(3), 798–803. doi:10.2307/1370491

Emerald ash borer. Retrieved October 24, 2016, from Government of Canada, (1) https://www.nrcan.gc.ca/forests/fire-insects-disturbances/top-insects/13377

Flower, C. E., Long, L. C., Knight, K. S., Rebbeck, J., Brown, J. S., Gonzalez-Meler, M. A., & Whelan, C. J. (2014). Native bark-foraging birds preferentially forage in infected ash (Fraxinus spp.) and prove effective predators of the invasive emerald ash borer (Agrilus planipennis Fairmaire). Forest Ecology and Management, 313, 300–306. doi:http://dx.doi.org.proxy3.library.mcgill.ca/10.1016/j.foreco.2013.11.030

Jennings, D. E., Gould, J. R., Vandenberg, J. D., Duan, J. J., & Shrewsbury, P. M. (2013). Quantifying the impact of woodpecker Predation on population dynamics of the Emerald Ash borer (Agrilus planipennis). PLOS ONE, 8(12), e83491. doi:10.1371/journal.pone.0083491

Kube, R. (2014). Downy woodpecker. Retrieved October 25, 2016, from https://www.allaboutbirds.org/guide/Downy_Woodpecker/lifehistory

Laframboise, K. (2016, April 5). Montreal pours cash into fight against emerald ash borer. Retrieved October 26, 2016, from News, http://www.cbc.ca/news/canada/montreal/montreal-emerald-ash-borer-budget-1.3521363

Lawler, J. J., & Edwards, T. C. (2006). A variance-decomposition approach to investigating multiscale habitat associations. USGS, 108(1), 47–58. doi:10.1650/0010-5422(2006)108[0047AVATIM]2.0.CO;2

Lindell, C. A., McCullough, D. G., Cappaert, D., Apostolou, N. M., & Roth, M. B. (2008). Factors influencing woodpecker Predation on Emerald Ash borer. The American Midland Naturalist, 159(2), 434–444. doi:10.1674/0003-0031(2008)159[434:fiwpoe]2.0.co;2

Mueller, H. (2016, September 19). Basic facts about Woodpeckers. Retrieved October 25, 2016, from http://www.defenders.org/woodpeckers/basic-facts

Myczko, Ł., Rosin, Z. M., Skórka, P., & Tryjanowski, P. (2014). Urbanization level and woodland size are major drivers of woodpecker species richness and abundance. PLOS ONE, 9(4), e94218. doi:10.1371/journal.pone.0094218

Ornithology, C. L. of. (2002). Cornell Lab of ornithology. Retrieved October 25, 2016, from http://www.birds.cornell.edu/wp_about/biology.html

Rocha, R. (2015, January 6). A tree grows in Montreal? Most likely a maple. Retrieved October 24, 2016, from Montreal Gazette, A tree grows in Montreal? Most likely a maple

Rognan, C. Yellow-bellied Sapsucker. Retrieved October 25, 2016, from https://www.allaboutbirds.org/guide/Yellow-bellied_Sapsucker/lifehistory

Spring, L. W. (1965). Climbing and Pecking adaptations in some north American Woodpeckers. The Condor, 67(6), 457–488. doi:10.2307/1365612

Vierling, L. A., Vierling, K. T., Adam, P., & Hudak, A. T. (2013). Using satellite and airborne LiDAR to model woodpecker habitat occupancy at the landscape scale. PLOS ONE, 8(12), e80988. doi:10.1371/journal.pone.0080988

Ville de Montréal – borough Saint-Laurent – Emerald Ash borer. (2015, May ). Retrieved October 25, 2016, from Ville de Montreal, http://ville.montreal.qc.ca/portal/page?_pageid=8297,122605590&_dad=portal&_schema=PORTAL

Vyn, G. Pileated woodpecker. Retrieved October 25, 2016, from https://www.allaboutbirds.org/guide/Pileated_Woodpecker/lifehistory

Wood, C. L. (2016). Hairy woodpecker. Retrieved October 25, 2016, from https://www.allaboutbirds.org/guide/Hairy_Woodpecker/lifehistory

Wood, C. L. Red-bellied woodpecker. Retrieved October 25, 2016, from https://www.allaboutbirds.org/guide/Red-bellied_Woodpecker/id

Zhou, X. Q. Kong,C. W. Wu, Z. Chen. (2009). The Novel Mechanical Property of Tongue of a Woodpecker. Retrieved October 25, 2016, from Journal of Bionic Engineering 6 (2009) 214–218, www.sciencedirect.com/science/article/pii/S1672652908601262. doi: 10.1016/S1672-6529(08)60126-2


Picture References

Belhumeur, R. (n.d.). Yellow-bellied Sapsucker Adult female [Digital image]. Retrieved from https://www.allaboutbirds.org/guide/Yellow-bellied_Sapsucker/id

Hanrahan, C. (n.d.). Hairy woodpeckers (Picoides villosus) scaling bark from trees [Digital image]. Retrieved from https://fletcherwildlifegarden.wordpress.com/2013/01/21/hairy-woodpeckers-picoides-villosus-scaling-bark-from-trees/

(n.d.). Downy Woodpecker Adult male [Digital image]. Retrieved from https://www.allaboutbirds.org/guide/Downy_Woodpecker/id

Jobes, W. (n.d.). Red-bellied Woodpecker Adult male [Digital image]. Retrieved from https://www.allaboutbirds.org/guide/Red-bellied_Woodpecker/id

(n.d.). Northern Flicker Male (Red-shafted) [Digital image]. Retrieved from https://www.allaboutbirds.org/guide/Northern_Flicker/id

Northern Flicker [Digital image]. (n.d.). Retrieved from http://www.wildbirdhabitatstore.com/index.php?option=com_content&view=article&id=79:northern-flicker-2&catid=2&Itemid=195

Oyer, B. (n.d.). Hairy Woodpecker Adult male [Digital image]. Retrieved from https://www.allaboutbirds.org/guide/Hairy_Woodpecker/id

(n.d.). Just Your Average Beautiful South Florida Day [Digital image]. Retrieved from https://palmbeachcountynaturally.wordpress.com/2012/03/23/just-your-average-beautiful-south-florida-day/

Smith, M. (n.d.). Pileated Woodpecker [Digital image]. Retrieved from http://www.audubon.org/field-guide/bird/pileated-woodpecker

Sharpe, M. (n.d.). Pileated Woodpecker Adult male [Digital image]. Retrieved from https://www.allaboutbirds.org/guide/Pileated_Woodpecker/id










Solving a Myth: Do Lichens Know What Direction They’re Growing In?


Growing up in Canada, our culture has always praised the pioneers who colonized what we call home. Lichens, in the way the first settlers tell us about a community, tell us a lot about an ecosystem. They are bioindicators for air quality and perhaps even cardinal direction. Join us in our investigation as we discuss our interest in the latter myth.

A Little History

In 1867, Simon Schwendener proposed that lichens were composed of two organisms (Honegger, 2000). A study was conducted by Bässler et al (2015) just last year focusing on one lichen specie over 16 countries showing that fungi can select for specific photobionts which is likely a driving factor for such immense lichen diversity. Though lichens are known to be pioneer species, the first colonizers of a disturbed environment, they’re also quite sensitive to changes in temperature and levels of precipitation (Bässler et al, 2015). Some scientists are looking at lichens to predict the effects of climate change in certain ecosystems. Most recently, a paper was published by Spribille et al (2016) proving that many species of lichens have a third symbiotic partner: yeast. Even with this sink of knowledge the most experienced lichenologists must admit defeat when it comes to surveying lichens in large plots. The problem is they can be virtually anywhere. In a study by Vondrák, J., et al. (2016), it is explained that many species are very specialized and are found only in one place, for example, high in the forest canopy . Their canopy sampling was mostly from fallen twigs; clearly there were missed opportunities to complete their species list. In our own research we have a similar problem since our sampling was only at breast height and not the entire height of our tree replicates.


Symbiosis in lichens involve a mycobiont (fungus), and a photobiont (photosynthetic agent, usually algae), in one structural unit. The fungi provides a comfortable habitat for the algae and the algae provides food from photosynthesis. Lichens are distinguished by the shape, size, colour and specific combinations of mycobiont and photobiont; classification is based on their fungal component. Lichens generally assume one of four morphologies: foliose, fruticose, crustose and squamulose. The differentiation is usually made by examining the thallus, the main body (Shukla, Upreti et al. 2013).

picture1Figure 1a) Blue green foliose lichen with two-dimensional lobes. b) Fruticose lichen with an erect and shrubby thallus. c) Green cup-like erect thallus of a fruticose lichen. d) Crustose lichen with an irregular-crack shape, seen through a magnifying glass.

The foliose growth form is one that we came across very often in the field. It’s characterized by a leafy two-dimensional thallus, more or less flattened, that remains attached to the substrate by adherent rhizines, which act as anchors rather than roots since they don’t take up nutrients (Brodo, Sharnoff et al. 2001). This wavy sheet-like structure usually gives rise to circular lobes (Figure 1a). A fruticose lichen presents a three-dimensional thallus that can be either erect (Figure 1b, c) or pendant. Its tangled appearance and the absence of rhizines leads to instability (Brodo, Sharnoff et al. 2001, Lepp 2011). Crustose lichens, as their name suggests, are crusty-looking and firmly attached to their substrate. They can be smooth or broken forming cracks that divides the lichen in patches (Figure 1d) (Brodo, Sharnoff et al. 2001).



Reproduction can either be sexual, meaning both parents contribute genes to the progeny, or asexual, the progeny is identical to one parent, or both, depending on the species (Lepp 2011). In sexual reproduction of lichen the fungal partner produces two kinds of reproductive structures, or fruiting bodies, resembling tiny button mushrooms (Brodo, Sharnoff et al. 2001, Lepp 2011). The first, apothecia, has a bowl shape with spores on the inside surface as shown in Figure 2a.

The other, perithecia, is shaped like a fig and has an internal spore producing layer hidden inside the thallus that releases spores by an opening on the top where the fig’s stem would be (Figure 2b) (Brodo, Sharnoff et al. 2001).

picture2Figure 2 a) Black apothesia with a cup shape. b) Perithesia shown here as small black dots .

Those spores, once released, will need to land on the right photobiont, in the right habitat to be able to produce viable lichen, a challenging feat. Vegetative, or asexual, reproduction is when lichen grows from a broken fragment of the thallus. In this case the lichen is a clone of its parent; this is the most efficient way of reproducing (Lepp 2011).


Distribution of lichen is strongly correlated with its status of pioneer species. Lichens can survive surrounded by a thick layer of snow in Antarctica and extended periods of drought in the McMurdo valleys (Australian Government, 2016), conditions that would annihilate many other fierce species, even us. They grow on lots of surfaces like tree bark, rocks, and even on the outside walls of McGill’s Macdonald Campus.

Our Research Question

Is there any correlation of lichen abundance and diversity with cardinal direction on tree bark?


Step 0: We call this step zero because it must be completed before going into the field. Create a data sheet to record all data.

Step 1: Select an open area with several trees that appear to have even sun exposure on all sides.

Step 2: Tag trees that have been quickly inspected to see if they have equal exposure to the sun on each cardinal direction. In other words, walk around the tree and look.

Step 3: Stand by the tree. Use the compass to identify which side of the tree faces north. Imagine the tree as the center of the compass.

Step 4: Accurately measure Breast Height (1.3m) from the ground to the bottom of the grid square. Place the grid up against the tree following the direction previously determined.

Step 5: Observing the grid, use one grid square equals to 0.5%. Estimate approximately the amount of lichen coverage and identify the species involved; indicate the dominant specie. For identification, refer to Lichen Structure mentioned above. Record results.

See our video explaining our methods!


We observed lichens on every cardinal side of the tree but it remains to be seen if some lichen species prefer a specific cardinal side. We will need to revisit the number of visible species on many replicates since our identification techniques have broadened since the beginning of our research.

Stay tuned and follow us on twitter (@ImLichenIt16) to see how the cardinal direction myth pans out.

figure-14Figure 3. The lichen team


1- Australian Government, D. o. t. E. a. E., Australian Antarctic Division (2016). “Lichens.” from http://www.antarctica.gov.au/about-antarctica/wildlife/plants/lichens.

2- Bässler, C., et al. (2016). “Contrasting patterns of lichen functional diversity and species richness across an elevation gradient.” ECOG Ecography 39(7): 689-698.

3- Brodo, I. M., et al. (2001). Lichens of North America. New Haven, Yale University Press.

4- Duketoday (2011). “Lichen evolved on two tracks, like mammals and marsupials.” from https://today.duke.edu/2011/05/lichen.

5- Honegger, R. (2000). “Simon Schwendener (1829-1919) and the Dual Hypothesis of Lichens.” The Bryologist 103(2): 307-313.

6- Lawrey, J. D. (1994). Lichen Allelopathy: A Review. Allelopathy, American Chemical Society. 582: 26-38.

7- Lepp, H. (2011, 24 December, 2015). “Lichen.” from http://www.cpbr.gov.au/lichen/index.html.

8- Lutsak, T., et al. (2016). “Mycobiont-photobiont interactions of the lichen Cetraria aculeata in high alpine regions of East Africa and South America.” Symbiosis Symbiosis 68(1-3): 25-37.


10-Seneviratne, G. and I. K. Indrasena (2006). “Nitrogen fixation in lichens is important for improved rock weathering.” J Biosci Journal of Biosciences 31(5): 639-643.

11- Shukla, V., et al. (2013). “Lichens to biomonitor the environment.”

12- Spribille, T., et al. (2016). “Basidiomycete yeasts in the cortex of ascomycete macrolichens.” Science 353(6298): 488-492.

13- Vondrák, J., et al. (2016). “Methods for obtaining more complete species lists in surveys of lichen biodiversity.” NJB Nordic Journal of Botany 34(5): 619-626.

14- Yahr, R., et al. (2006). “Geographic variation in algal partners of Cladonia subtenuis (Cladoniaceae) highlights the dynamic nature of a lichen symbiosis.” New Phytologist 171(4): 847-860.





Buckthorn Abundance Along Edge Habitats: Morgan Arboretum


1Figure 1: One of the tree lines we studied, on a beautiful day.


The invasive European shrub known as Buckthorn, has been recently identified as detrimental to North American ecosystems (Mascoro, 2007). There are two types, Common buckthorn (Rhamnus cathartica) and Glossy buckthorn (Fragula alnus) (See figure 2). In the context of our research we use the umbrella term “Buckthorn”. Our research was conducted at the Morgan Arboretum. It is one of the largest green spaces on the island of Montreal, located on the western tip of the island. The Arboretum is a curated space, offering unique opportunities to study Buckthorn in an area with high tree diversity. Little work concerning Buckthorn has been conducted in this area, presenting new avenues of discovery for management.


Invasive plants are introduced in either an intentional or unintentional manner. There is strong evidence suggesting that Buckthorn was introduced to North America from Europe intentionally due to its ornamental and medicinal properties (Kurylo, 2012).

Buckthorn introduction most likely occurred in the 1800s in the United States. For the following century, Buckthorn gained popularity as an ornamental “hedge” shrub and vast amounts of seed were sold throughout North America (Kurylo, 2012). Only in the 21st century have the negative impacts of its aggressive invasion been noted.

Physical Description:

2Fig 2: Mature Common Buckthorn (Rhamnus cathartica) on the left and infant glossy buckthorn (Frangula alnus) on the right.

The Common Buckthorn is a deciduous shrub with branches growing nearly opposite from each other. These branches frequently converge into short thorns in R. cathartica. While in F. alnus terminal thorns will not be present. In both, the foliage is ovular (Kurylo et al, 2007). However, the leaf veins and arrangement differ between species. R cathartica has 4-8 lateral veins that all go to the leaf tip, while F. alnus has more common lateral leaf veins. Also, F. alnus’ leaves are mildly shiny and wavy (NCC, 2016).

The distinctive dark grey bark present in both species will commonly have a exposed yellow layer, making it easily misidentified as a native cherry. In the springtime, this shrub blossoms miniscule, honey-scented flowers. Purple-black berries ripen in September and October, and stay well into the winter. The unhabituated Buckthorn will maintain green foliage well into the winter (Knight et al, 2007), making winter identification easy.

Reproduction/ Regeneration:

Buckthorn prefers soils of high alkalinity (Kurylo  et al, 2007). These are the types of soil the species thrived in Central Europe before it made its way over to North America.

Buckthorn thrives in two different conditions: shady understory and open conditions (Knight et al, 2007). Buckthorn is shade tolerant, which mean it can still seed and survive in low-light levels. However, its survival is not nearly as great as in open conditions which consists of more light (Kurylo et al, 2007). Buckthorn takes advantage of open canopies, forest edges and disturbed areas within the forest and grow.

Buckthorn will deposit seeds and grow beneath its mature ‘trees’ (Knight et al, 2007). Due to a preference for disturbed habitats, Buckthorn forms dense thickets on edge habitats such as field treelines. Reproduction occurs via animal-aided seed dispersal (birds and rodents) (Knight et al, 2007).

Ecological Effects:

In North America, Buckthorn can: be harmful to agriculture (Ontario government 2012); inhibit tree regeneration, and decrease herbaceous ground cover (Knight et al, 2007).  Buckthorn hosts two main agricultural pests, Oat rust (pathogenic fungus) and the soybean aphid (insect), these affect both quality and yield of nearby crops.

Buckthorn escaped its natural predators when it invaded North America, notably insect specialized predation (Knight et al, 2007). Shade tolerance lets Buckthorn to thrive even when the canopy in closed, allowing the plant to dominate the understory and overstory of edge habitats (Knight et al, 2007). The leaf litter cover is greatly reduced under Buckthorn, an association with earthworms is assumed to be the cause (Knight et al, 2007).

Buckthorn leaves contribute to soil nitrogen concentration (Knight et al, 2007). Buckthorn exudates an allelopathic compound called emodin which has several effect on it environment, and may deter insects and herbivores. The allelopathic effect of emodin on nearby plants and soil microorganisms seems to be compensated by the increased soil nitrogen (Knight et al, 2007). The natural work of succession may be the best way to control Buckthorn abundance (Cunard, 2009).

Research Question:

Buckthorn’s ecological effects, its invasive nature, and that its abundance remains relatively unstudied in Quebec were the primary motivations for our study. We sought to answer the question:

How does Buckthorn abundance vary across edge habitats in the Morgan Arboretum?


3Figure 3: The forests, plantations, and collections within the Morgan Arboretum with our study areas indicated.

The first step in our research was identifying the locations to study. Because Buckthorn is so apt for both shady understory and open conditions it can be highly abundant along and within the treeline of open fields. We selected 4 fields within the Arboretum, and sampled 4 consecutive 5m*5m quadrats along the center of each side of each treeline. The quadrats spanned 5m away from the field into the treeline. Our independent variables were the cardinal direction that each treeline faced, and the dominant tree species of each quadrat (both noted on site, also referenced from figure 3). The direction that each treeline faced was considered because it has a considerable effect on solar exposure.

The abundance of Buckthorn in each quadrat was measured by counting the number of individual stems. Stems that protruded from others, stems without foliage, and/or stems that did not have the characteristic woodiness of Buckthorn were not counted. Notes were made of major features in the quadrats and tree lines.

4Figure 4: Two of our group members, Filip and Joseph, during one of our field excursions. Joseph is confirming his identification of a Buckthorn specimen, Filip was inspecting the quadrats to ensure that they were formed by straight lines.


Our study can contribute to the understanding of Buckthorn abundance in Quebec, and help understanding how varying tree species and the ‘direction-faced’ along a tree line can affect Buckthorn abundance. If replicated over a significant time period, our data could help the application of management techniques by the arboretum staff, as well as help to narrate the natural history of the Morgan Arboretum.



Cunard, C., & Lee, T. D. (March 23, 2009). ‘’Is patience a virtue? Succession, light, and the death of invasive glossy buckthorn (Frangula alnus)’’. Biological Invasions, 11, 3, 577-586. Retrieved October 26th 2016: http://mcgill.worldcat.org/oclc/4669700809

Fagan, M. E. and D. R. Peart (2004). “Impact of the invasive shrub glossy buckthorn ( Rhamnus frangula L.) on juvenile recruitment by canopy trees.” Forest Ecology and Management 194(1): 95-107. Retrieved October 22nd 2016: http://mcgill.worldcat.org/oclc/4930686271

Gassmann, A. and I. Tosevski (2014). “Biological control of <i>Rhamnus cathartica</i>: is it feasible? A review of work done in 2002-2012.” JEN Journal of Applied Entomology 138(1-2): 1-13. Retrived October 23rd 2016: http://mcgill.worldcat.org/oclc/5525679451

Knight, Kathleen, Jessica Kurylo, Anton Endress, J Stewart, and Peter Reich. “Ecology and Ecosystem Impacts of Common Buckthorn (rhamnus Cathartica): a Review.”Biological Invasions. 9.8 (2007): 925-937. Retrieved October 10th 2016: http://mcgill.worldcat.org/oclc/440551978

Kurylo, J. and A. G. Endress (2012). “Rhamnus cathartica : Notes on Its Early History in North America.” nena Northeastern Naturalist 19(4): 601-610. Retrieved October 5th 2016, Online: http://mcgill.worldcat.org/oclc/4936884841

Kurylo, J.S., K.S. Knight, J.R. Stewart, and A.G. Endress (2007). “Rhamnus cathartica: Native and Naturalized Distribution and Habitat Preferences”.  The Journal of the Torrey Botanical Society.  134(3): 420-430. Retrieved September 27th 2016.            http://www.jstor.org.proxy3.library.mcgill.ca/stable/20063933?seq=2#page_scan_tab_contents.

Mascaro, J. and S. A. Schnitzer (2007). “Rhamnus cathartica L. (Common Buckthorn) as an Ecosystem Dominant in Southern Wisconsin Forests.” Northeastern Naturalist Northeastern Naturalist 14(3): 387-402. Retrieved October 23rd 2016: http://mcgill.worldcat.org/oclc/4630521679

Nature Conservancy Canada (NCC). (c2016). Glossy Buckthorn. Nature Conservancy Canada. [Online]. Retrieved October 3rd 2016. http://www.natureconservancy.ca/en/what-we-do/resource-centre/invasive-species/glossy-buckthorn.html?referrer=https://www.google.ca/

Ontario invasive plant council (2012). “Common Buckthorn” [Online], Retrieved October 10th 2016. https://dr6j45jk9xcmk.cloudfront.net/documents/3192/stdprod-104385.pdf




Feeding Habits of The Eastern Grey Squirrel in Urban and Forest Habitats

Squirrels are one of the most recognizable animals in Canada. According to The Natural History of Squirrels (Gurnell 1987), three different types of squirrels exist: flying, ground-dwelling and tree squirrels. They all evolved from a common ancestor living in North America during the Eocene epoch (54 to 57 Million years ago), and then spread out, colonizing other areas and evolving into a wide varieties of species.

In taxonomy, squirrels belong to the rodent (rodentia) order, inside the bigger mammalian group. One of the diverse rodent family is the Sciuridae family which contains the Sciurinae subfamily (as tree squirrels), which contains the Sciurus genus. This genus is then divided into twenty-eight species, S. carolinensis being one. The classification goes on, differentiating five subspecies of the S.carolinensis, also called Eastern grey squirrel (Lawniczak 2002).

Our attention will be focused on the Eastern Grey squirrel (Sciurus carolinensis), a medium sized tree squirrel species, that usually weights around 300-710g, found from the Gulf of Mexico to the southern parts of Quebec, and Ontario (Sandro 2008). This species can easily be observed in city parks and backyards, and is also found in wild deciduous forest at the Morgan arboretum.


We are observing our study species at three site at the Morgan Arboretum (the experimental groups), and at one urban backyards located in Anjou (the control group). Grey squirrels make caches by carrying food in their mouth to a suitable location, sometimes digging in several places before selecting a site (Hopewell and Leaver 2008). However, proximity with humans (by deforestation and urbanization) sometimes denatures these foraging behaviors to such a point that some squirrels are now living in towns, and feeding on human garbage (Bowers and Breland 1996). The goal of our project is to try to analyze to some extent the impact of human activity on squirrels.

Figure 1. Squirrels found in a rural area (left) and an urban area (right).

Research Question

In the arboretum, the squirrels mainly have access to nuts like acorns, samaras and hickory nuts. Whereas the urban squirrels have access to diverse food choices, and do not have to cache as much food as wild squirrels considering that they can rely on garbage and bird feeders during winter (Thompson and Thompson 1980). We wanted to compare the different feeding behavior between wild and urban squirrels. We placed two feeders in three different locations in the Morgan arboretum and in one location in an urban backyard. Considering that acorns are a big part of the wild squirrel nutrition in the arboretum, if a new type of nut is introduced in the arboretum (the peanut), which the wild squirrels usually do not have access to in Québec, what type of nuts, the foreign (peanuts) or the native (acorns), will the wild squirrel choose compared to the urban one? This is relevant because, human activity such as the introduction of open garbage bins in cities could have possibly altered the foraging behavior of the eastern grey squirrel. Our research question is then: Does the feeding habit of Sciurus carolinensis differ between an urban and forest habitat?

 Methods and Materials

To construct the squirrel feeders, we first cut off the bottom of a clean two liter soda bottle. Two holes were then cut on the side of the initial hole to allow the squirrels to take the nuts. The bottle was then glued to a plastic plate; the plastic plate had three holes at each end to allow water to drain when it rained. A wire was attaches to the top of the bottle, around the cap, to allow the feeder to hang in the tree.

3Figure 2. An example of a feeder.

In the Morgan Arboretum we located three different environments (sugar maple forest, beech forest and mix beech forest) where two feeders were placed in each environment; one with peanuts and the other, acorns. To place the feeders in a tree we used a pulley system. To a 10m long rope was attached a counterweight that we threw over the shortest and most accessible branch on a designated tree. Once a feeder was full with either acorns or peanuts, we attached it to the end of a wire that was in turn attached to the 10m rope, and pulled the feeder close to the branch, about 3 to 4 m high, so that it was not easily accessible to other animals. The loose end of the wire was then wrapped and tied around a nearby tree so that the feeder was secure. To check the feeders, the rope was untied and the feeders were slowly let down, as to not let any nuts fall off. Once the recordings were done and the squirrel feeder refilled, it was pulled back up into to tree. Each feeder was checked 3 times a week by members of the group. The weight of the nuts that were left over in the feeders was recorded, as well as the new weight of the nuts used to refill the feeder. Each feeder originally had the same amount of nuts at the beginning of the experiment. The feeders were all refilled based on the amount of nuts gone from the last reading.

Team members carried observational analysis, sitting far enough from the feeders as to not disturb or scare the squirrel’s, but close enough to record their activity. The observation was completed in periods of two and a half hours, with teammates rotating between feeders at the Arboretum. The objective of this watch is to not only record squirrel activity, but to ensure that squirrels are in fact the ones foraging in the placed feeders, and not other species of animals.

Expected Results

Considering that the wild squirrel are used to the acorn that they can naturally find in the Arboretum we expect them to feed more on the acorn feeders than on the foreign peanuts. Furthermore, we expect to see a higher selection for the foreign peanuts in the urban control, than at the experimental sites of the Morgan Arboretum.



Bowers MA, Breland B. 1996. Foraging of Gray Squirrels on an Urban-Rural Gradient: Use of the Gud to Assess Anthropogenic Impact. Ecological Applications. [Accessed 2016 October 27]; 6:1135–1142. http://onlinelibrary.wiley.com.proxy3.library.mcgill.ca/doi/10.2307/2269597/abstract. doi: 10.2307/2269597

Gurnell J. 1987. The natural history of squirrels. New York, N.Y: Facts on File. 201 p.

Hopewell LJ, Leaver LA. 2008. Evidence of Social Influences on Cache-Making by Grey Squirrels ( Sciurus carolinensis ). Ethology. [Accessed 2016 October 26]; 114:1061–1068. http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0310.2008.01554.x/abstract. doi: 10.1111/j.1439-0310.2008.01554.x

Lawniczak, M. 2002. Sciurus carolinensis. Animal Diversity Web. [Accessed October 27 2016]. http://animaldiversity.org/accounts/Sciurus_carolinensis/

Morgan arboretum [Internet]. [Updated 2013 November 15; Accessed 2016, October 26]. http://www.morganarboretum.org/nature-en/mammals.html

Sandro B. 2008. Introduction of the American grey squirrel (Sciurus carolinensis) in Europe: a case study in biological invasion. Current science. [Accessed 2016 October 26]; 95(7): 903-906. https://www.researchgate.net/publication/242084905_Introduction_of_the_American_grey_squirrel_Sciurus_carolinensis_in_Europe_A_case_study_in_biological_invasion

Thompson DC, Thompson PS. 1980. Food habits and caching behavior of urban grey squirrels. Canadian Journal of Zoology. [Accessed 2016 October 26]; 58:701-710. http://www.nrcresearchpress.com/doi/abs/10.1139/z80-101#.WBKijpPhDox. doi: 10.1139/z80-101






Medicinal Plants in the Morgan Arboretum

Dominant tree species within a forest have resounding effects on the developmental direction an ecosystem takes. Different types of trees can affect the soil properties, water, light availability, and in our case, understory growth. A large portion of understory plants have medicinal properties, making them of special interest to humans both historically, having been used by Indigenous communities for centuries, and possibly in the future as sources of new medications, especially with the growing trend towards ‘natural’ remedies (Ehrlich 2013). For our project we asked the question: “What understory medicinal plants are present based on dominant tree species in the Morgan Arboretum, and what is the local biodiversity of these plant species?”. Although medicinal plants comprise a wide variety of species, we are focusing on the Canada Mayflower, Solomon’s Seal, Baneberry, and Twisted Stalk.


To test our hypothesis that we would find more biodiversity of medicinal plants in mixed wood deciduous forests we used multiple 100 meter long transects. They extended into the forest at random intervals, perpendicular to a demarcated pedestrian trail on which we observed our tree species. We first identified and recorded the diameter at breast height of the tree species present along our transects. Then we identified the herbaceous species, noting the ones that were recorded to have some medicinal value. Each species had to be within a meter of the transect line on the ground, and their position was recorded. Each transect was located within the Morgan Arboretum, in Beech Maple, sugar maple and coniferous forests. We also observed and recorded necessary information required for the later identification of unknown species. After collecting enough data, we were then able to discern which medicinal species were most prominent among specific types of trees.

3Figure 1. The green stars indicate transects 1A and 1B-Beech maple forest. Red stars indicate transects 2A, 2B and 2C-coniferous forest. The black stars are transects 3A, 3B and 3C- Sugar maple forest.

Natural history

The Canada Mayflower, or Wild lily-of-the-valley (Maianthemum canadense) is a small, perennial plant with two to three smooth heart-shaped leaves. In the spring they have small white flowers. It grows in cool woods, in deciduous, coniferous, and mixed forests, as well as clearings throughout Quebec, except for far North. Some individuals do not produce flowers, and is simply a single leaf rising from rhizomes that form continuous undergrowth. The berries are edible but can be purgatives in excess. The Canada Mayflower was also used by Amerindians as an infusion to relieve headaches and as a gargle for sore throat (Montreal Botanical Garden).

1Figure 2. a) Maianthemum canadense. Commonly known as The Canada Mayflower, found in our first transect of the Morgan Arboretum. b) Polygonatum multiflorum. Commonly known as Solomon’s Seal, also found at the first transect of the Morgan Arboretum.

One of the most prevalent of the observed medicinal plants is Polygonatum multiflorum, commonly known as Solomon’s Seal. The plant is not native to Canada and is a perennial that typically grows anywhere and prefers lighter soil and a shady spacial distribution (A Modern Herbal). The roots and the shoots are of medicinal significance. The species is most well known for treating pulmonary consumption and bleeding lungs. However, it can also act as an astringent, demulcent, or tonic to treat menstrual pains, stomach inflammation and dysentery.

White Baneberry, Actaea pachypoda, is a perennial also known as “Doll’s-eyes” due to its distinctive round white berry with a black spot that resembles a pupil, carried by thick, bright red pedicels. It is present only in Southern Quebec and Saguenay, and prefers rich woods, maple groves, and the edges of rivers. Despite its toy-like appearance, the berry is highly poisonous and purgative. The root was once used to make a tea for women who had just given birth for labour pains, as well as for headaches, coughs, menstrual irregularities, colds, and constipation (Montreal Botanical Garden).

2Figure 3. a) Actaea pachypoda. Also known as Baneberry, found at our second transect of the Morgan Arboretum. b) Streptopus amplexifolius, commonly known as Twisted Stalk. This sample was found in the Morgan Arboretum at Transect 2C.

Streptopus amplexifolius is a perennial better known to some as Twisted Stalk. It is also called Wild Cucumber because of the taste of the edible green shoots. The plant also produces red to yellow berries, which are edible and have a taste similar to watermelon. In significant quantities, the berries can be used as a laxative or a purgative, but most often the root and foliage are used as a tea. This treats a wide variety of ailments such as an analgesic for internal pains, to induce labor, and to treat kidney problems and gonorrhea (Montana Plant Life).

Scientific Context

The dynamic of diversity and abundance of herbaceous plants in the understory are strongly influenced by tree cover. The variables on which tree cover depends are stand composition, time since major disturbances and available sunlight (Bartemucci P., 2006). A dense overstory usually composed of hardwoods and conifers will have a negative effect on understory vegetation as the amount of transmitted light and precipitation, direct or throughfall, reaching the forest floor are limited (Elsevier, 2008). For these reasons, young mixed deciduous forests allow for more light transmission to the ground and soil moisture regardless of disturbances or topography. Nonetheless, an “old” climax forest will have a steady herbaceous composition. Although the climax forest will be less diverse, as the factors affecting the herb layer are more stable (Brewer R., 1980). Furthermore, studies show that the diversity present in coniferous forests is essentially due to two factors. The first is the amount of precipitation reaching the ground rather than solar radiation, since the canopy density doesn’t change throughout the seasons (Wiley , 1969). The second factor is a lower soil pH, which can often impact what grows in the understory (Berger A. & Puettmann K., 2000). There are other variables to consider such as soil properties other than pH, and factors related to the herbaceous species like their growing season or their tolerance to shade (Brewer R., 1980). Deciduous forests host a lot of spring ephemerals that benefit from the increased sunlight in late-spring and early summer before the canopy reforms (Moore M., & Vankat J., 1986). The vertical profile of light transmission exhibits a decent impact on understory diversity but due to the complexity of the subject no clear conclusion have been drawn so far (Bartemucci P., 2006).  Within this ecological research there is not a lot known on how the specific local forest types such as Beech, Maple, and Spruce, affect the medicinal biodiversity on the forest floor. Our goal is to fill in these gaps of information so that these relationships can be applied on a local forest system level.



Anderson R. C. “Herbaceous Response to Canopy Cover, Light Intensity, and Throughfall Precipitation in Coniferous Forests.” Ecology 50.2 (1969): 255. Web.

Barbier S. “Influence of Tree Species on Understory Vegetation Diversity and Mechanisms Involveda Critical Review for Temperate and Boreal Forests.”Forest Ecology and Management 254.1 (2008): 1. Web.

Bartemucci P. “Overstory Influences on Light Attenuation Patterns and Understory Plant Community Diversity and Composition in Southern Boreal Forests of Quebec.” Canadian Journal of Forest Research / Revue Canadienne De Recherche Forestire 36.9 (2006): 2065. Web.

Berger A. L., Puettmann K. J. “Overstory Composition and Stand Structure Influence Herbaceous Plant Diversity in the Mixed Aspen Forest of Northern Minnesota.” The American Midland Naturalist, vol. 143, no. 1, 2000, pp. 111–125. http://www.jstor.org.proxy3.library.mcgill.ca/stable/3082988.

Brewer, Richard. “A Half-Century of Changes in the Herb Layer of a Climax Deciduous Forest in Michigan.” Journal of Ecology, vol. 68, no. 3, 1980, pp. 823–832. http://www.jstor.org.proxy3.library.mcgill.ca/stable/2259458.

“Clasping-leaved Twisted-stalk – Streptopus Amplexifolius.” Clasping-leaved Twisted-stalk – Streptopus Amplexifolius. Plant-life.org, n.d. Web. 28 Oct. 2016. <http://montana.plant-life.org/species/strepto_ample.htm&gt;.

Moore M. R., Vankat J. L. “Responses of the Herb Layer to the Gap Dynamics of a Mature Beech-Maple Forest.” The American Midland Naturalist, vol. 115, no. 2, 1986, pp. 336–347. http://www.jstor.org.proxy3.library.mcgill.ca/stable/2425870.

  1. Grieve. “Solomon’s Seal.” A Modern Herbal. Botanical.com, n.d. Web. 28 Oct. 2016. <http://www.botanical.com/botanical/mgmh/s/solsea63.html&gt;.
  1. D. Ehrlich SE. 2013. Herbal medicine [Internet]. Phoenix: A.D.A.M., Inc.; [2015 June 11, cited 2016 Sept 27]. Available from: http://umm.edu/health/medical/altmed/treatment/herbal-medicine

Webmaster. “Plant of the Week.” Twisted Stalk. United States Department of Agriculture, n.d. Web. 28 Oct. 2016. <http://www.fs.fed.us/wildflowers/plant-of-the-week/streptopus_amplexifolius.shtml&gt;.

“Wild Lily-of-the-valley, Canada Mayflower.” Space for Life. Espace Pour La Vie, n.d. Web. 28 Oct. 2016. <http://espacepourlavie.ca/en/biodome-flora/wild-lily-valley-canada-mayflower&gt;.

“White Baneberry.” Space for Life. Espace Pour La Vie, n.d. Web. 28 Oct. 2016. <http://espacepourlavie.ca/en/biodome-flora/white-baneberry&gt;.


Saproxylic Invertebrate Diversity in Decaying Ash Trees Vs. The Stage of Decay

Trees decay at very slow rates over the space of decades and constitute as much as 10-25% of the above ground biomass in forests (Ulyshen, 2014). Dead wood is a significant factor in nutrient cycling and is a host to many organisms, from unicellular microorganisms to complex invertebrates (Franklin et al., 1997).

Organisms that depend on dead or decaying wood in their life cycle are called ‘saproxylic’ (Speight, 1989). Wood-inhabiting species are composed of fungi and insects. Insects that depend or live in decaying wood contain the orders of: Coleoptera (beetles), Diptera (flies), Hymenoptera (wasps, ants, bees), Isoptera (termites), Lepidoptera (moths), and Hemiptera (true bugs). Other than insects, members of the Order Nematoda (nematodes) can also be found living in decaying wood (Stokland et al., 2012).

The diversity of saproxylic fauna is determined by a variety of factors including; the species of tree, level of decay, stand age, and the cause of tree death (Langor et al., 2008). In a study by Dahlberg and Stokland (2004), it was found that in a large sample of saproxylic insects, a small percentage of them exhibited a preference to a specific tree species. This was due in part to tree composition. The structural or chemical factors in trees that affect host-tree relationships include lignin, hemicellulose content, and secondary compounds produced by the tree as a defense mechanism (Stokland et al., 2012). The latter constitute an important challenge for initial bark colonizers, such as bark beetles, which need to face the chemical defense system of the tree, highly present in the cells under the bark of recently deceased trees. Nevertheless, patterns of host-tree preferences are also linked to decay preference.

6Image 1: Some invertebrates found in decaying logs. The inverts found in this petri dish include:  Fire-coloured beetle larvae (pyrochroid Dendroides canadensis), centipedes, and other saproxylic feeders. (Identification retrieved from bugguide.net).

Saproxylic species which associate strictly with one host-tree occur at early stages of decay. Thus, saproxylic insects with more specific host-tree requirements are more often found in recently dead trees. Heavily decayed trees tend to support the diversity of saproxylic species with less specific host requirements (Stokland et al., 2012). As the physical and chemical properties change with the decomposition of the tree, invertebrate communities will change as well, as they have specific nutritional needs that are provided by different stages of decay.

The Morgan Arboretum is a reconstitution of many types of forests, the largest forest type being Sugar Maple-American Beech. A study by Williamson (1975), suggested that early colonizers (pioneers) of this type of forest are Ash trees, and since they are eventually outcompeted by Sugar Maple and American Beeches, we thought we would be most likely to find many fallen Ash trees at different stages of decay. Additionally, these trees may colonize a recently disturbed habitat eventually make a stand of Ash trees as a means of secondary succession.

Image 2: On the left, a primarily a Maple and Ash stand. This is the first forest we sampled from on our first data collection day.  Ash in red and Maple in pink.  On the right, a close up of Ash bark. Notice the signature ‘diamond’ or ‘X’ patterns in the bark.

Ash trees are also currently threatened by the Emerald Ash borer, a pest insect introduced from Asia. This pest has rapidly spread to a good proportion of the United States and Canada and has already killed millions of ash trees since its discovery in 2002 (BenDor et al. 2006).

Considering the increase in Ash tree death due to the Emerald Ash Borer, the sudden surge in fallen Ash could influence the saproxylic organisms that rely on these trees. A sudden increase in fallen ashes may be beneficial in the short term for saproxylic organisms that require them for their nutritional needs (Littlewood et al., 2014). Some orders such as: Hemiptera, Diptera, and Lepidoptera are obligate to Ashes and they may suffer devastating population crashes as they rely on a continual supply of these trees (Littlewood et al., 2014). Since the Emerald ash borer threatens Ashes in North America, it is important to learn more about the relationship between the saproxylic invertebrates and this type of tree.

Based on what we discovered above, we asked the following research question:

How does the level of decay in Ash trees affect the diversity of the saproxylic invertebrates that inhabit them?

Our Methods

To answer our research question, we established a scale to measure the different levels of decay of dead trees.


Sampling was done once a week for three weeks. We went to the Morgan Arboretum and sampled 17 dead ash trees. Logs were randomly chosen and we sampled multiple 30 by 30 cm2 plots on the trunk, chosen via a random number generator. For each tree chosen, we determined their level of decay (using the table above) and we measured the length and circumference. Invertebrates were collected on ⅔ of each log. We used a chisel and mallet to peel off the bark and retrieve any invertebrates we found.

Each specimen found was accounted for and was released back where we found them afterwards. We took pictures of every different invert we found to identify them later in addition to the level of decay of each tree.

See our video explaining our sampling method!

Image 3: Collecting the invertebrates on the left and data inventory of the invertebrates on the right.

We noticed that the level of decay greatly impacted the diversity of inverts we found. We did not come across any decaying ash trees that scored a 4 or a 5 as per our table (above), but we came across many that ranged from 1-3. We expected there to be less inverts present in newly fallen trees (scoring a 1) but we were surprised to find that there were a decent amount present (even though the bark was extremely hard to remove). We mostly found potato bugs, millipedes and some spiders (which are not saproxylic). Under the bark of trees that scored a 2 or a 3 or between both, we found many creatures including; earthworms, beetles (very few though), a variety of beetle larvae, millipedes, centipedes, some fly larvae, and potato bugs.

Our research and findings so far have shown that Ash trees prove to be good host to a variety of saproxylic invertebrates, which worried us at first since there was not a lot of literature on the host-specificity of saproxylic inverts to Ash trees. The vast majority of the literature we found in terms of Ash trees was linked to the Emerald Ash Borer, so we were relieved to find that Ash trees served as an adequate feeding, hibernation, and cover site for many saproxylic organisms.

7Image 4: A. Wireworm (click beetle larvae), B. Millipede, C. Xylophagus larvae, D. Click beetle larvae, E. Potato bug, F. European Nightcrawlers (earthworms). These were all found under the bark of our sample Ash trees. (Identification retrieved from bugguide.net).


Cited by:

BenDor, T. K., Metcalf, S. S., Fontenot, L. E., Sangunnett, B., & Hannon, B. (2006). Modeling the spread of the Emerald Ash Borer. Ecological Modelling, 197(1–2), 221-236. doi:http://dx.doi.org/10.1016/j.ecolmodel.2006.03.003

Bughunter. (2005, 23 January 2008). Wireworm (Click Beetle Larvae). Retrieved from http://bugguide.net/node/view/14440

Dahlberg, A., Stokland, J. N. (2004). Substrate Requirements of Wood inhabiting species: a compilation of 3600 species. (Vol. Report 7, pp. 75): Skogsstyrelsen, Jönköping.

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Intraspecific Competition within the Sugar Maple Species, Acer Saccharum, through the Assessment of Population Density and Size

There are approximately 150 species of maple trees located within the Northern Hemisphere, with 10 of them native to North America (NRCAN-2015). One of the most commonly grown species of maple is the Sugar Maple (Acer saccharum). Sugar maple is a keystone species, meaning it is a significant ecological element of Northern hardwood forests, like those we can find in the Saint-Lawrence lowlands. As its leaf is represented on our Canadian flag, it is widely exploited due to its maple syrup production as well as its wood quality (Houston, 1999). Its wood is described as hard and durable material which is suitable for manufacturing furnitures, paneling and flooring (Tirmenstein, 1991). However, a decline in sugar maple growth has been observed since the early 1970’s due to its heavy industrialization (Bishop et al., 2015).


Sugar maple trees can live up to approximately 200 years and grow up to 35 m high and measure up to 90 cm in diameter (NRCAN-2015). Sugar maples have simple leaves (single), in opposite arrangement on the twigs. They are usually five-lobed but leaves with three or four lobes are also possible. Leaves are of a dark yellowish-green colour on the adaxial surface and a lighter green on the abaxial surface of the leaf. They are generally smooth on both surfaces. The margins in between the lobes are shallow and smooth, which distinguishes them from the leaves of the similar-looking red maple (Acer rubrum), which has much more serrated and sharp lobe margins. Additionally, lobes on the sugar maple have a “U-shaped” connection whereas the lobes on the red maple have a “V-shaped” connection (Luzadis,Gossett-1996). The sap of the sugar maple is transparent as opposed to the white sap of the invasive Norway maple, thus making it easier to differentiate the two. Trunks are straight and often branch-free for two-thirds or more of their height. The crown is narrow, round-topped, and the roots go deep and spread wide. The tree produce paired samara fruits with wings 30–35 mm in length (NRCAN-2015).

sugar-maple-leaf-norway-maplebarkFigure 1:  On the left we see a comparison between a Norway maple leaf (left) and a sugar maple leaf (right). The discolouration of the sugar maple is due to fall conditions. The norway maple stays dark green throughout fall since it is not native to Canada and hence it is not adapted to seasonal changes. On the right is sugar maple bark.

The bark on young trees is smooth and dark grey. As it grows, it develops long, vertical, firm, irregular ridges curling outward along one side, somewhat scaly and can turn into a dark brown color.


Sugar maples are typically found in temperate regions and are a climax species (Fleming, 1995) exclusive to the Northern American Continent, facing temperatures that range from -40°C to 37°C (Luzadis & Gossett, 1996). Sugar maples can be found in elevations ranging between 914 m and 1676 m in warmer regions (Luzadis & Gossett, 1996). Acer Saccharum grows in a wide variety of plant communities throughout Eastern North America; amongst mixed and or pure tree stands where they most commonly flourish alongside white ash, black cherry, basswood, ironwood, beech, white pine, red oak and yellow birch (Fleming, 1995).

Sugar maples require moist soils with good drainage; they do not thrive in shallow waters and dry soils. Acer Saccharum needs a soil that allows for deep root growth and can be found on either acidic (pH 3.7) and or neutral (pH 7.3) soils; the prefered pH is between 5.5 to 7.3. The Sugar Maple participates in nutrient recharge of the soil by shedding its leaves periodically which furthermore decays into organic matter (Luzadis & Gossett, 1996).

figure-4-panoramic-view-of-a-pure-sugar-maple-standFigure 4: Panoramic view of a pure sugar maple stand. 

Research Question

“How does the density and basal area coverage of overstorey sugar maple trees affect the growth and abundance of understorey trees?”

Study Area

The study is taking place at the Morgan Arboretum, which is located near the Macdonald Campus situated in the St. Lawrence Lowlands. The arboretum contains 245 hectares of forested land inhabited by wildlife including plants, insects, rodents, amphibians and large mammals (Morgan Arboretum, 2014).

Understorey and overstorey vegetative surveys focusing on sugar maples, but also including other trees species, are being conducted. We set up four plots measuring 50m by 50m within the arboretum, two of which are within a pure sugar maple tree stand while two others are in a mixedwood stand near the yellow trail indicated in Figure 4. Four square plots measuring 10 m x 10m were randomly placed within the 50m x 50m plots.


figure-5-50m-by-50m-plotFigure 3: A 50m by 50m plot which contains four randomly placed 10m by 10m plots and three circular subplots randomly set up within the 10m x 10m plot to measure understorey tree species.


Within the 10m x 10m plots, we counted and measured all of the overstorey trees with a diameter breast height (DBH) of 10 cm and higher. Using the data collected, the relative dominance, the relative density and the basal area of sugar maples will be calculated.


Three circular subplots with a radius of 2 m were randomly placed within the smaller 10m x 10m square plots. The studied species of trees with a DBH of less than 10 cm within the subplots were recorded and placed in three categories. Class A consists of trees with a height below 0.5 m, class B includes trees between 0.5 and 1.5, Class C includes understorey above 1.5 m. The data from the understorey survey will be used to calculate the frequency and the relative density of the sugar maple tree species.



Figure 4: Location of the 50m by 50m plots within the Morgan Arboretum.

Here is a video that summarizes the methods.


According to our observations and data collection so far, we noticed that in the mixedwood tree stands, the plots tend to be more densely populated with understorey sugar maple trees, other woody plants and shrubs. Meanwhile, in the pure sugar maple stands, the trees tend to be more evenly distributed with little to no understorey trees. We hypothesized that intraspecific competition seems stronger in pure sugar maple stands than in mixed tree stands. Overstorey trees seem to outcompete understorey trees by taking a significant amount of basal area to develop. This hypothesis is in accordance with recent studies which have found that sugar maple trees are under higher competitive pressures in pure stands over mixed tree stands (Martin-Ducup et al. 2016). Similarly, another study suggests that competition is more fierce among conspecifics and that radial growth of sugar maples is affected by the distance between conspecifics (Henrick et al., 2009). When the distance between two sugar maples was smaller, the competitive pressures were higher thus supporting our idea that sugar maple growth is favored when conspecifics are at an optimal distance from each other which allows for more basal area to be covered.


Work Cited

Bishop, D. A., C. M. Beier, N. Pederson, G. B. Lawrence, J. C. Stella, and T. J. Sullivan. “Regional growth decline of sugar maple (Acer saccharum) and its potential causes.” Ecosphere 6(10):179, 2015.  October 24, 2016. <http://dx.doi.org/10.1890/ES15-00260>.

Hartmann, H., Beaudel, M., Mazerille, M.J., Messier, C. “Sugar maple (Acer saccharum Marsh.) growth is influenced by close conspecifics and skid trail proximity following selection harvest.” Forest Ecology and Management. Vol. 258.5. 20 August 2009, pp. 823-831. Web. October 25, 2016.

Houston, David R. “History of Sugar Maple Decline.” Sugar Maple Ecology and Health: Proceedings of an International Symposium, 1999. pp. 19-26. Web. October 27, 2016. <http://www.treesearch.fs.fed.us/pubs/13134 >.

Luzadis, V.A. and  Gossett, E.R. . “Sugar Maple.” Forest Trees of the Northeast. Cooperative Extension Bulletin 235. Cornell Media Services. 1996. pp. 157-166. Web. October 2, 2016. <http://dx.doi.org.proxy3.library.mcgill.ca/10.1016/j.foreco.2009.05.028>.

Martin-Ducup, Olivier, Robert Schneider & Richard A. Fournier. “Response of sugar maple (Acer saccharum, Marsh.) tree crown structure to competition in pure versus mixed stands.” Forest Ecology and Management, vol. 374, August 15, 2016, pp. 20-32. Web. PDF. October 27, 2016 <http://ac.els-cdn.com/S0378112716302213/1-s2.0-S0378112716302213-main.pdf?_tid=079b45de-9c78-11e6-9855-00000aacb362&acdnat=1477595182_c74bd4060a8506606669a0027f828da0>.

Morgan Arboretum. “Welcome to the Arboretum”. October 30, 2014. Web. October 25, 2016.  <http://morganarboretum.org/>.

Natural Resource Canada. Sugar Maple Factsheet, 2015. Web. October 28, 2016.<https://tidcf.nrcan.gc.ca/en/trees/factsheet/86>.

Sir Sanford Fleming College. “Sugar Maple. Sir Sanford Fleming College, 1995. Web. September 28, 2016. <http://www.lrconline.com/Extension_Notes_English/pdf/sgr_mpl.pdf>.

Tirmenstein, D.A. “Acer saccharum.” The Fire Effects Information System. USDA, Forest Service, Intermountain Research Station, Intermountain Fire Sciences Laboratory, Missoula, Montana, 1991. Web. October 24, 2016.  <http://www.fs.fed.us/database/feis/plants/tree/acesac/>.


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