Thus, to develop a reasonable estimate of species richness and dominance, researchers must sample over several years. These studies also have documented that certain collecting techniques work better for some fungi than others, which emphasizes the need to develop standardized sampling protocols for collecting data on fungal species' richness and fruiting patterns. This approach shows great promise for directly investigating the effect of certain fungi on tree health. These data, however, are based only on aboveground information, and there is still some question about how well the appearance of fruitbodies growing under a particular tree predicts what fungi are forming mycorrhizae with that tree at that time. The studies mentioned in this article illustrate the range of work in the United States on assessing diversity and determining possible changes in fruiting patterns of macrofungi.
More work is needed to document the status and trends of macrofungi in North America.
These data are vital because of the integral role that macrofungi play in forest systems as decomposers and recyclers, plant pathogens, mutualists, and food for small mammals, and because of the growing commercial importance of these fungi. Conservation of fungi in Europe. Pages 211-234 in D.N. Pegler, L. Boddy, B. Ing, and P.M. Kirk, eds. The Royal Botanic Gardens, Kew, U.K. Bigelow, H.E. 1982. North American species of Clitocybe .