ABSTRACT
This chapter discusses some of the ecological processes effected by macro basidiomycete fungi. Their role in establishing and maintaining soil fertility is twofold, in that they are implicated in rock fracturing and dissolution and as saprotrophs. In the first role, they may be important in providing the mineral component of soil, releasing nutrients and creating ion exchange sites on these particles. In the second role, they are largely responsible for the decomposition of plant litters (especially recalcitrant litters of wood) and mineralizing the nutrients contained within these materials, particularly in forested ecosystems. In tree dominated ecosystems, basidiomycetes are important mycorrhizal associates. The combined roles of maintaining soil fertility and assisting nutrient uptake both significantly underpin plant primary production in terrestrial ecosystems. The plant pathogenic role of basidiomycetes is largely due to non-mushroom forming genera, except for some tree pathogens that are also partly saprotrophs, such as Armillaria. Pathogens have been deliberately omitted from this discussion. Due to the longevity of both saprotrophic and ectomycorrhizal mycelial structures and the production of macro-fruitbodies, there has been interest in the role of these structures in accumulating pollutant metals for increased retention (lowering mobility) and in concentrating metals into fruiting structures to reduce access by other organisms. The enzyme capabilities of basidiomycetes also allow them to be candidates for the breakdown of organic pollutants, as these enzymes have evolved to decompose complex plant organic materials, some of which have similarities to pollutants.
