落葉広葉樹林内の斜面における大型土壌動物について : II.ツリミミズ科とフトミミズ科のミミズ類について

抄録

TSUKAMOTO, Jiro (For. Exp. Sta. Kochi Pref., Kochi). 1985. Soil macro-animals on a slope in a deciduous broad-leaved forest II. Earthworms of Lumbricidae and Megascolecidae. Jap. J. Ecol., 35 : 37-48. Species richness of earthworms on the studied slope was comparable to that in the best mull soils of Europe, in spite of the strong acidity. Species number did not differ substantially between the ridge part with "mor-type" humus and the bottom part with "mull-type" humus. Biomass of earthworms was larger at the bottom than on the ridge, reflecting the better conditions at the bottom. The difference in earthworm biomass in the studied site was smaller than that in the mull and mor soils of Europe. This difference seemed to be related to differences in the amount of precipitation and in the background for differential development of mull and mor soils in the two places. Vertical distribution of earthworms as a whole clearly differed between the ridge and bottom of the slope. This difference seemed to be affected by the presence of absence of the F (H)-layer and by the difference in soil depth originated from the difference in the mode of sedimentation of the parent material of the soil between the two parts of the slope. Individual earthworm species had respective habitat preference in soil profile. This preference also seemed to be affected by the factors mentioned above.