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.
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