Ecological Patterns of Wood-Inhabiting Myxomycetes in a Natural Forest of the Kamikochi, the Hida Mountain Range, Central Japan

Abstract

The ecology of lignicolous myxomycetes on fallen dead wood has never been clearly demonstrated in an intact forest. We compared the occurrence of myxomycete sporocarps on the dead wood of deciduous broad-leaved trees (BW) and coniferous trees (CW) to determine species preferences for tree types and wood decay stages. Surveys of sporocarps were performed during summer and autumn 2011–2013 in a conserved forest of the Northern Japan Alps. We recorded 89 taxa (87 species, two varieties): 60 species on BW and 64 species on CW. Between seasons, the percentage similarity of myxomycete occurrence was low (0.239), while between tree types it was higher (0.463). Ordination of the assemblages using non-metric multidimensional scaling demonstrated that myxomycete occurrence changed seasonally and exhibited tree type preference. Fortynine species (55% of the total) exhibited seasonal and/or tree type preferences. A majority of the species occurred on the intermediate decay stage of both tree types, but 38 species were correlated with particular decay stages of either CW or BW. The tree types contain wood parts at various decay stages, creating microenvironments that seasonally provide heterogeneous microhabitats for myxomycetes. Such diverse microhabitats on a local scale can promote myxomycete diversity in a natural forest.