異なる2つの林分におけるキシャヤスデ幼虫の生息密度と土壌微生物量との関係

抄録

Relation between larval train millipede density and soil microbial biomass under two different forest. Ayu Toyota and Nobuhiro Kaneko (Soil Ecology Research Group, Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Yokohama, 240-8501, Japan). The relationship between larval train millipede, Parafontaria laminata (Attems, 1909) density and soil microbial biomass in larch, Larix kaempferi (Lamb.), oak, Quercus mongolica Fischer ex Turcz. var. grosserrata (Bl.) Rehd. et Wils. forest soils was examined. The larvae were found in soil at high density as all individuals in a population consisted of a single cohort (same age) in the study site. The effects of the train millipede on soil microbial biomass were observed for two growing seasons at 6th instar and 7th instar larval stages. Distribution of both instars was similar between the larch and oak forests. Sixth instar larvae reduced soil microbial biomass with increasing density in the larch forest, whereas they gave a non-linear density effect on soil microbial biomass in the oak forest. However, at 7th instar, there was no decrease in soil microbial biomass even at high density spot. These effects of larval train millipede on soil microbial biomass were considered to result from feeding behavior, such as geophagous at 6th instar larvae, and litter and soil mixed feeding at 7th instar larvae.