Geographical distribution of myxomycetes on coniferous deadwood in relation to air temperature in Japan

This study obtained information on the biogeographical distribution of lignicolous myxomycetes in temperate regions in Japan. It examined how climatic variables are related to patterns of occurrence in myxomycete communities. Sixty-four taxa were recorded on coniferous wood in 15 forest sites in summer. Common species that were abundant and widely distributed in Japan included Stemonitis axifera, Lycogala epidendrum, and Cribraria cancellata. In addition, Lindbladia cribrarioides was characteristic on dead Pinus densiflora wood in southwestern Japan. The species diversity index (H′) of the myxomycete communities was positively correlated with the annual mean temperature. The distribution of myxomycete communities was analyzed using nonmultidimensional scaling (NMDS). The ecological nature of the gradients expressed by the first two NMDS axes was that the first axis was found to correspond strongly to changes in the average minimum temperature and the latitude, and the second axis was related to a complex of factors, including altitude. The relative abundance of certain species in a myxomycete community on Japanese red pine changed in relation to the annual mean temperature, e.g., Lycogala epidendrum correlated negatively while Stemonitopsis hyperopta did so positively. We conclude that air temperatures can be used to predict the geographical distribution of lignicolous myxomycetes in this temperate region of Japan.