ABSTRACT
Some metals, particularly toxic metals, may accumulate in soils and in aquatic food webs, negatively affecting microorganisms and ecosystem functions, including nutrient cycling. The effect of metals in soils is a product of inherent toxicity due to chemical properties, as well as the availability of the metals in solution. Many aspects of fungal growth, metabolism, and cell differentiation are affected by metals (Gadd 1993). Toxic metals require immobilization in nonbioavailable forms to become less toxic. Toxic effects are apparent in fungi at the individual species level (gene expression and physiology and activity of enzymes), population levels (ecotypes), and community levels. The challenge is to understand how toxicity at each of these levels affects the structural and functional diversities in soil and aquatic environments.
