Myxomycetes on the bark of living trees and their distribution along a rural-urban gradient.

Myxomycete distribution along urban-rural gradients remains to be studied in detail. The ancient plant has been mainly planted in urban parks and green areas in Japan, and it provides new habitats for myxomycetes on its growing tree bark. Here, we examined myxomycetes on bark along urbanization gradients, estimated by land-use coverage types. Survey sites were selected at 20 locations in western Japan, where the bark was sampled from 10 trees at each site. The bark samples were cultured in 10 Petri dishes per tree using the moist chamber technique. Myxomycete fruiting colonies occurred in 71% of cultures, and 44 species were identified across surveys. occurred at all sites, with the next most abundant species being and . Twenty-two myxomycete communities ordinated using non-metric multidimensional scaling showed a significant negative correlation with building coverage and bark pH, increasing along the first axis. Relative abundances of and positively correlated with increasing building coverage. Overall, urbanization causes alternation of the myxomycete community structure without diversity loss, and intermediate urbanization diversified species diversity on tree bark.