Spread of fungal communities in Finland

 

Mushrooms are  everywhere in Finland, from polypores to tasty forest floor morsels. But what do these community structures actually look like as a whole? Ecologists know that the richness and abundance of organisms vary with different environmental conditions; the tapestry of an old forest will be totally different from a tree plantation. But these patterns have been considerably less studied for fungi than other kingdoms, and their unique and also less known dispersal abilities complicate the picture further.

The purpose of my master's thesis was to get a basic picture of the spread of fungal communities across middle and southern Finland, specifically how the communities change over distances (large and small) and between different habitat patches (urban and natural). To see what fungi are there, my collaborators and I took samples of soil and spores in the air. We did this in five locations across the country, attempting to cover a decent spread of landscapes, and in each location there were six plots (divided between urban, natural, and edge), to pick up the finer scale changes.

Spore sampler

The site of my sampling was near Lammi Biological Station, where I stayed for two weeks at the end of August 2019. This beautiful area served as the base, from which I would drive to Lahti every few days for my urban samples and where I would do some basic sample processing, coordinating, and writing in the evenings. Field data collection, as always, was my favorite part of the studies. I spent the following winter analyzing the fungal OTUs I received after DNA sequences of my samples returned. Much of the time was spent going over and over the location based charts, curiosity finally being assuaged of what all mushroom species I might find in Finland.

 Then finally, this spring I submitted my thesis with all of my findings. Between Helsinki and Joensuu, fungal communities do not show distance decay to the rate I would have expected. Perhaps it's due to the relative homogeneity of the landscape at the larger scale? But this is speculation, and I am eager to see future studies that reach into the mechanisms and explanations, as well as replicating similar methodology in totally separate regions of the world. Anyway, the perhaps more striking results were the differences between urban and natural habitat types, providing even more evidence of the drastic effects of anthropogenic change on other populations.

Colleagues in my research group ran parallel analyses from my data, focused more on this aspect. It led to a paper published in ISME Journal, for which I am a co-author, titled 'Fungal communities decline with urbanization—more in air than in soil'.

 I am grateful to the foundation for providing the grant that made this research possible.

Brittni Joette Crosier is a 2019 LBAYS grant recipient