Visitors to the Reserve this season have noticed an unusual abundance and variety of mushrooms popping up everywhere, given the increase in rainfall this season. In addition to enjoying their delightful shapes and colors, our staff have feasted on chicken-of-the-woods, chanterelles, oyster and black trumpet mushrooms. Fungi play an important role in forest ecosystems and are the largest living organisms on earth. By definition, they are a diverse group of eukaryotic single-celled or multinucleate organisms that live by decomposing and absorbing the organic material in which they grow, producing fruit, called mushrooms, which provide food for wildlife.
Not all mushrooms grow above ground. For instance, truffles that grow on the roots of red spruce trees provide an important food source for the endangered Carolina northern flying squirrel, found in the high elevation spruce-fir forests of the Southern Appalachian Mountains. These truffles (Elaphomyces spp.) have a strong odor when mature, allowing the squirrels to locate dense areas of truffles by scent. (Loeb et al., 2000) Southern Highlands Reserve partners with federal and state agencies as a founding member of the Southern Appalachian Spruce Restoration Initiative (https://southernspruce.org) to restore the habitat of Carolina northern flying squirrel and many other species by growing red spruce trees from cones collected on public land.
A mushroom you are more likely to see this time of year is the Jack-O-Lantern mushroom (Omphalotus olearius). Its bright orange and poisonous fruit can be found growing around tree stumps in the fall. One interesting fact about this mushroom is that it is bioluminescent, meaning that it glows in the dark, emitting a color similar to a firefly. The purpose of this chemical reaction is to attract nighttime insects that then spread spores, using compounds similar to those fireflies use. The difference is that bioluminescent mushrooms contain enzymes that have the ability to create other glowing colors. This could prove useful for bioluminescent imaging and other, not yet conceived, uses.
Mushrooms help our native animals and enchant our minds. Staff at the Reserve have found ways to incorporate mycelium into projects and best management practices. For example, we add a powder containing endomycorrhizal, ectomycorrhizal and Trichoderma fungi to our potting mix for red spruce trees. This helps with water and nutrient uptake for the new seedlings. This spring, we implemented a composting project in the greenhouse. Staff were introduced to the idea of using mushrooms as a composting component that Diana Hiles, our horticulturist, learned from Max Dubansky of Backbone Farm, in Maryland. He uses wine cap mushrooms (Stropharia rugoso-annulata) to speed up compost on his organic farm. With further research, our staff have started a mushroom composting simulation in a 33-gallon barrel, filling it with wood chips and fresh green debris from our compost pile. Then, second-generation grain spawn of the wine cap mushroom are layered into the mix, creating a mycelium lasagna. Yum!
The goal of the experiment is to have the mycelium decompose the contents of the barrel and produce fruit. The barrel is kept in the green house because the mycelium need warm temperatures to colonize the barrel; the mushrooms it will produce are edible and might interest more than just hungry gardeners! Once fully colonized, the barrel’s contents will be mixed into the large compost pile. Wine cap mushrooms have been found on site prior to this project so we can verify that they are endemic. The spent mycelium will aid in the time it takes our debris to compost and add nutrients to the compost that can then be used in the landscape. Caring for the old and fostering the new are an important part of what we do to keep SHR the special ecosystem it is.
Not all fungi are beneficial to us or other plants as many of you know from seeing azalea gall on your native azaleas or powdery mildew on your roses. In fact, the largest organism in the world is a fungus, Armillaria solidipes or A. ostoyae. This honey fungus causes Armillaria root disease, killing conifers and creating more food for itself along the way. This single fungus, with an identical genetic make-up, resides in Oregon’s Malheur National Forest, encompassing 2,384 aces. It’s estimated to be about 2,400 years old due to its growth rate but could be as old as 8,650 years old! (Casselman 2007)
At the end of the day, fungi are only one component of our ecosystem. It takes many other organisms to make the cogs of Mother Nature turn, including all of us. The everyday choices we make impact the world we share. Thank you for supporting organizations like ours, being environmentally responsible and trying to leave the world better for the generations to come.