懸垂土壌におけるササラダニ群集の多様性

抄録

I reviewed the structures of oribatid-mite communities (Acari: Oribatida) in suspended soils and biotic and abiotic factors causing the diversity. Oribatid mites are one of the most numerically dominant groups of arthropods in suspended soils, from which we often can collect no less than 50 species. The species diversity of oribatid communities in suspended soils may be lower than that in the forest floor. However, characteristic structures and patchy distribution of suspended soils allow diverse oribatid communities to be established, thus may help to maintain or enhance the diversity of oribatid communities in arboreal ecosystems. The proportions of the oribatid species common to the two habitats (suspended soil and forest floor) account for ca. 25-50%, which are independent of the forest type and/or climatic zone. In a subtropical forest, the oribatid fauna in the suspended soils associated with bird's nest ferns was more similar to that in the forest floor than to the faunas in the other arboreal habitats (leaves, branches, bark). Thus, although suspended soils can provide a unique habitat for some specialized species, the existence of suspended soils might not dramatically raise the overall species diversity of oribatid communities in the whole forest.