This Field Note is by Joe Brehm, Rural Action Environmental Education Director
The cycles of warm rain and sunshine stimulate serious summer fecundity in Southeast Ohio forests. So much of the seasonal explosion of life is centered around trees – oaks, maples, hickories, beech, hemlock, and many others – as they grow leaves and produce sugars from the most basic elements: water, air, earth, and fire (sun). These leaves feed billions of caterpillars, leafhoppers, beetles, and other insects, which feed millions of birds and other insectivores. Sugars made through photosynthesis in the leaves trickle down through the inner bark and into root systems, where cicadas suckle from subterranean burrows by the thousands of thousands.
As it were, tree-made sugars’ journey does not stop there; trees in our forests have such intimate relationships with fungi that the tree roots and fungal strands become one. Mushrooms enter the tree roots themselves, and in many cases even penetrate at the cellular level. They become so intertwined that scientists have a word for the plant/fungi roots: mycorrhizae (an article in the latest issue of Fungi Magazine explains this extremely well). It turns out that these many mushroom species store somewhere in the neighborhood of 30% of carbohydrates produced by trees. In return the fungi help the tree by absorbing moisture (mycelium are thinner than even the trees’ root hairs and can capture water in the tiniest pockets within soil and bedrock) and minerals important for tree growth (mycelium can go down further into the earth than tree roots to reach these precious minerals).
This time of year – the wetter days of summer – is exceptional in that we can see evidence of these mycorrhizal relationships in the form of fungal fruiting bodies. As you may expect from our old hills, these fungal fruits are diverse, colorful, and exciting to find. An upland forest in full myco-glory is akin to the explosion of spring flowers, salamander migration to vernal pools after the first warm rain, or the peak of bird migration. Beauty is abundant and it’s easy to find something exciting every few steps: a reddish orange bolete the size of a baseball cap, a studded white Amanita abrupta with its veiled stem, pale orange ruffled chanterelles, or the sunset-colored cap of a fishy milkcap slowly erupting through leaf litter.
My own journey learning about fungi began with inspiration from Southeast Ohio’s own Martha Bishop, who teaches mycology at Ohio University and led monthly fungi hikes for us two years ago. She introduced to me and dozens of others some of the common families responsible for all of this: Russulaceae (Brittlegills and Milkcaps), Boletaceae (including Porcinis), Amanitaceae (many are poisonous), and Cantharellaceae (Chanterelles). In his must-have field guide, Appalachian Mushrooms, Walter E. Sturgeon points out that many North American species are named after their European look-alikes and mycologists are now teasing apart taxa by DNA analysis. Species shuffling is sure to ensue.
In our long-term bioblitz of Wayne National Forest’s Athens Unit, volunteer citizen scientists have observed approximately 529 species of fungi to date. This total includes 22 in the Russulacea family, 20 Amanitaceae, 9 Cantharellaceae, and 30 Boletaceae. Many other species observed in the bioblitz are saprophytic, meaning they have a lifestyle more stereoptical of fungi and digest dead wood or leaf litter. One species even destroys live insects and millipedes; you can see the whitish fungi emerging from between the body segments of this millipede.
The current show put on by mycorrhizal fungi fruiting throughout the forest has dragged me out of some mental dog days of summer, and stand as poignant reminders about what is really going on in our forests, much of which is invisible to us or any other creature, save perhaps for the cicadas. Partnerships between fungi and trees, old as time immemorial, give us so much. It makes me think more about what I can do for them in return.
(Field Notes is an occasional series that takes readers into local forests to learn about our natural world. Become a citizen scientist and join the more than 475 volunteers who have contributed close to 16,000 observations via iNaturalist to our “bioblitz” of the WNF’s Athens Unit, documenting roughly 3,400 species of plants, insects, fungi, mammals, birds, and more. You can join us by following instructions here.)