Ecological aspects of myxomycetes associated with white and brown wood rot on coarse woody debris in subalpine coniferous forests in Central Japan

We investigated factors affecting the community composition of lignicolous myxomycetes in dead wood with white and brown rot through summer and autumn surveys in a subalpine forest in Central Japan. In both seasons, wood had decayed to a softer state under brown rot than under white rot. The pH of wood with white rot was nearly neutral, while wood with brown rot was weakly acidic. Wood pH was lower in summer than in autumn. Forty-two myxomycetes taxa in 19 genera were identified in 302 fruiting-body colonies; white rot yielded 31 taxa and brown rot 24 taxa. Species diversity was higher on wood with white rot than on wood with brown rot. The effect of wood hardness on species composition depended on season. Several species exhibited a preference for one of the rot types. The substrate conditions associated with brown rot limit myxomycetes species diversity.