Ecology and Distribution of Lepiotaceous Fungi (Agaricaceae) - A Review

Lepiotaceous fungi form relatively fragile basidiocarps with white, rarely coloured, spores. Most are saprotrophic forest-floor dwellers that grow in the lower litter layers of the soil, and probably decompose lignin and cellulose. They occur worldwide, with many representatives in tropical and temperate regions, and a few species in arctic-alpine areas and in deserts. Most taxa are agaricoid, though a relatively small number of secotioid variants exist. Because of their relative rarity, the clustering together of many species in limited habitats, and the differences in species composition along latitudinal transects, lepiotaceous fungi may be vulnerable to changes in the environment, both on a local (habitat destruction) and on a global scale (climate change). Sister taxa occur in different parts of the temperate zones of the Northern Hemisphere, indicating that vicariance events might have played a role in speciation. A few species have a very extended distribution, and those species occur either in man-made habitats or else in cooler habitats. Many ecological features of the lepiotaceous fungi are unknown, including the survival rates and colonization success of spores, nutrient and temperature requirements, longevity and size of genets. Conservation of existing diversity calls for policies underpinned by new ecological research, more taxonomical studies, and more recording projects.