• Mushrooms Growing in the Woodsfungus image by Alistair Dick from Fotolia.com
  
  Most of us picture wild mushrooms when we think about fungi in the woods. These fruiting bodies belong in one type of fungi, but the woods contain two other types we seldom see or consider as fungi. Wood-rotting, mycorrhizal and parasitic fungi all inhabit the woods, and each has a vital role to play in the forest environment.
  
  

Facts

• Fungi do not engage in photosynthesis, so they cannot produce their own food. Instead, they depend on being able to absorb nutrients from dead or decaying plant and animal material. Most woodland fungi prefer damp, shady conditions since they are not dependent on the sun for growth. Wood, leaves, soil and animal waste are examples of food supplies for fungi. Often reproducing with spores, fungi prosper after winds carry the spores to new feeding areas.
  
  

Wood-Rotting

• One of the more familiar types of fungi is referred to as wood-rotting. These include the mushrooms and fungi observed covering dead tree limbs and fallen logs as well as those that pop up in open ground. Wood-rotting fungi are vital to the life of the forest, because their job is to consume decaying plant material from the forest floor. Surviving on dead organic waste is called saprophytic feeding. Wood-rotting fungi are saprophytic feeders that break down sticks, dead leaves and dead trees, eventually converting them into soil.
  
  While mushrooms are visible evidence of the presence of wood-rotting fungi, most of the real work of these organisms occur beneath the dead tissues of fallen trees. This is where the fungus is at work collecting nutrients and converting decaying matter. Many fungi produce strands of stringy root-like material called hyphae, which are the primary food collectors.
  
  Puff balls, toadstools, edible and poisonous mushrooms all belong to this type of fungi. Leaf molds and molds that grow on other organic matter in the woods also fall into the wood-rotting type of fungi.
  
  

Mycorrhizal

• Mycorrhizal fungi have developed symbiotic relationships with other plant life in the woods, particularly with trees. These fungi will often weave their hyphae into a mat called mycelium, which wraps around and sometimes even penetrates tree roots. Mycelium absorbs nutrients from the soil and passes on to the tree what it doesn't need. The tree's root system provides a structure to which the mycelium can cling. Sometimes the mycelium will produce a fruiting body that we observe as mushrooms growing close to the base of trees.
  
  Another example of a symbiotic relationship is lichen. Not simply one organism, lichen is made up of an alga and a fungus. They exist harmoniously together, helping each other to thrive. The fungus in lichen would be described as a mycorrhizal fungus.
  
  

Parasitic

• Parasitic fungi consume nutrients from living trees and eventually cause the tree to rot. Dutch elm disease is an example of a parasitic fungus. The disease-causing fungus lives inside the tree and typically gives little indication it is present until the tree begins to show signs that it has been attacked. The fungus chokes off the elm's ability to distribute water through its internal system.
  
  In the woods, bracket fungi can sometimes be seen as large, shelf-like growths on the sides of trees. The parasitic fungi responsible attack mature trees, growing deep inside but eventually manifesting as the growth on the tree's exterior.