Stability, ephemerality and dispersal ability: microarthropod assemblages on fungal sporophores

Abstract

A comprehensive analysis of the microarthropod fauna from fungal sporophores revealed a series of recurrent patterns demonstrating the non-random structure of these assemblages. Despite the existence of a strong species-area relationship from sporophores of certain fungi, particularly among perennial species, several small sporophores always maintained a more diverse microarthropod fauna than fewer large sporophores of equivalent total area. A consistently high degree of overlap in microarthropod species occurrence between larger and smaller sporophores was indicated by the presence of highly significant nested subset structure. The fauna fromHeterobasidion annosumsporophores was the most nested, followed byHypholoma fasciculareand a collection of pooled agarics, respectively. When the fauna was split into functional groups, microphytophages were always significantly nested in their distributions but, when significant, macrophytophages and panphytophages had stronger nested hierarchies. Non-random organization was least evident among predatory species. Microarthropods had significantly ordered distributions on sporophores of various fungi. Many species occurred on perennialH. annosumsporophores of all sizes while others had more restricted distributions. Most species from very ephemeral agarics, including those which were widely distributed onH. annosum, were restricted to a small number of larger sporophores. The pattern fromH. fascicularewas intermediate; most species had narrow distributions and were present only on larger sporophores, except a small number of more widely distributed species.