FUNCTIONAL DIVERSITY IN FUNGI

Diversity has various meanings but generally they reflect the variatio n in species assemblages within a community. Species establish interpo pulation relationships that lead to stable community structure, and st able and resilient communities by definition contain a certain level o f diversity. Communities with too great or too little diversity predic tably undergo rapid change. Studies of fungal diversity have been limi ted by taxonomic and logistical difficulties in collecting and definin g fungal individuals and species. Succession of fungi on substrates, s easonal fluctuations, inconsistent isolation techniques, and other con siderations have also led to problems in assessing fungal species dive rsity. Although the problem has now been identified it is not likely t hat significant additions to our taxonomic knowledge will soon be usef ul in saving rapidly disappearing ecosystems. However, calculations of fungal diversity are not limited to taxonomic information. Several ap proaches provide measurements of functional diversity in situations wh ere taxonomic information is poorly defined. These include using binar y biochemical and physiological descriptors to characterize isolates, evaluating enzymatic capabilities for utilizing particular substrates and extracting DNA or RNA from the soil or other substrate and probing for genes that code for functional enzymes. Such functional approache s can provide timely information on the contribution of fungi to commu nity diversity and toward the establishment of predictors of community stability. This paper reviews the problems in assessing fungal divers ity and evaluates potential techniques for determining fungal diversit y from a functional perspective.