Mushrooms in the Woods

Fungi, neither plants nor animals, have a kingdom of their own, and there are over 1,000 species in northern Illinois.  Fungi have no roots, leaves, flowers, stems, nor chlorophyll.  They do not make their own food, but obtain nutrients from decaying organic matter.  Most are never seen, living underground or inside other species.  For many fungi, when it is time to reproduce, they grow an aboveground fruit called a mushroom.

Hymenophore, that produce spores, are located near the top of the mushroom.  A spore is a small, usually single-celled, reproductive unit able to grow into a new fungi without sexual fusion with another individual.  Spores can move about by wind, water, or insects.  Mushrooms are classified into one of two groups depending on how spores are released.  Club-fungi, basidiomycetes, drop their spores from the exterior surface of their club-like caps.  Sac-fungi, ascomycetes, shoot their spores outward from inside a sac-like structure under the mushroom’s cap.

Different types of fungi can be found in a forest ecosystem.  Saprophytic fungi feed on dead organic matter, helping decomposition and returning nutrients to the soil.  Mutualistic fungi work with a host plant to benefit both organisms.  An example critical to many forest species in our area is the association of fungi and plant roots known as mycorrhizae.  Plants provide food in the form of carbohydrates to the fungi.  In return, fungi made of long slender tubes, looking like a spider’s web, attaches itself to the plant’s root system, increasing the root’s surface area and allowing more water and nutrients to be absorbed.

In addition to providing beneficial services to plants, fungi play an important role in maintaining healthy habitat for many area wildlife species.  Tree cavities, created from decomposing wood in snags, are used for shelter by birds, small mammals, and insects.  Rotting logs found on the forest floor offer food, shelter, and protection for salamanders and frogs.  Carpenter ants build their nests by hollowing out a cavity in rotting wood.

The largest living organism in the world is a fungus in Oregon, covering an area three-and-a-half miles in diameter and estimated to be 2,400 years old.  In addition, at 6 million tons annually, mushrooms are the fifth largest crop in the United States.  It is generally accepted that mushrooms are slowly disappearing as are forested areas, but none are listed as threatened nor endangered because so little is known about them.  Consider taking along a mushroom field guide on your next woodland walk.