Characteristics of litter and soil arthropod communities at different successional stages of tropical forests
不同演替阶段热带森林地表凋落物和土壤节肢动物群落特征

In order to understand the relationship between soil arthropod community structure and floor litter at different successional stages of tropical forests, we surveyed the floor litter and the soil arthropods in a 23-year secondary forest, a 35-year secondary forest and a primary seasonal rainforest of Xishuangbanna, SW China in September 2001. Soil arthropods were extracted from the litter by Tullgren funnel method. The results showed that both the quantity and quality (N and C/N) of litter in the 35-year secondary forest were higher than those of the 23-year secondary forest and the seasonal rainforest. Acari and Collembola were dominant groups (> 80%), while ants, Coleoptera, Diptera, and Archaeognatha were common groups in the three forests. A higher individual density and relative individual density of soil arthropods were found in the 35-year secondary forest (10,067 ind./m2 and 22.72 ind./g dry litter) compared to the seasonal rainforest (5,654 ind./m2 and 18.44 ind./g dry litter) and 23-year secondary forest (2,881 ind./m2 and 5,818 ind./g dry litter). Pielou and Shannon-Wiener index of soil arthropod community were significantly higher in the 23-year secondary forest, while the richness (Margalef index) peaked in seasonal rainforest, and the dominance index (Simpson index) in 35-year secondary forest was the highest. The soil arthropod community composition was similar among the three forests. The individual density (ind./m2) of soilarthropods were positively correlated with floor litter mass in three forests, and they were correlated with the standing stock of N of the floor litter in 23-year secondary forest, and the standing stock of N of the floor woody detritus in seasonal rainforest. We conclude that the development of soil arthropod community in tropical forests is closely related to vegetation succession, and the soil arthropod community structure can be regulated through plant litter during the forest succession process, but other environmental effects including predator effect and human disturbance should not be ignored.