STABILITY, EPHEMERALITY AND DISPERSAL ABILITY - MICROARTHROPOD ASSEMBLAGES ON FUNGAL SPOROPHORES

A comprehensive analysis of the microarthropod fauna from fungal sporo phores revealed a series of recurrent patterns demonstrating the non-r andom structure of these assemblages. Despite the existence of a stron g species-area relationship from sporophores of certain fungi, particu larly among perennial species, several small sporophores always mainta ined a more diverse microarthropod fauna than fewer large sporophores of equivalent total area. A consistently high degree of overlap in mic roarthropod species occurrence between larger and smaller sporophores was indicated by the presence of highly significant nested subset stru cture. The fauna from Heterobasidion annosum sporophores was the most nested, followed by Hypholoma fasciculare and a collection of pooled a garics, respectively. When the fauna was split into functional groups, microphytophages were always significantly nested in their distributi ons but, when significant, macrophytophages and panphytophages had str onger nested hierarchies. Non-random organization was least evident am ong predatory species. Microarthropods had significantly ordered distr ibutions on sporophores of various fungi. Many species occurred on per ennial N. annosum sporophores of all sizes while others had more restr icted distributions. Most species from very ephemeral agarics, includi ng those which were widely distributed on N. annosum, were restricted to a small number of larger sporophores. The pattern from H. fasicular e was intermediate; most species had narrow distributions and were pre sent only on larger sporophores, except a small number of more widely distributed species. (C) 1997 The Linnean Society of London.