The effect of thinning on the community structure and densities of soil animals in a chamaecyparis obtusa plantation

Abstract

In a Chamaecyparis obtusa plantation, we examined the effect of thinning on soil animal communities. The community composition and individual densities of soil animals were compared between a rich-understory plot with thinning management (the thinned plot) and a poor understory plot without thinning (the delayed thinning plot). Soil animals sampled from both the litter and soil layers were classified after collection by the Tullgren method. In both layers, the taxa in the delayed thinning plot were significantly poorer than those in the thinned plot. The densities of oribatida mites and collembolans, both of which were dominant taxa, were significantly lower in the delayed thinning plot than in the thinned plot for both litter and soil samples. Our results suggest that lack of management of forests such as no thinning has a negative effect on the community composition and density of soil animals in the forest floor.