[Soil arthropod communities in different successional tropical secondary forests in Xishuangbanna]

Studies on the soil arthropod community structure and its seasonal variation in four types of secondary forest, including Macaranga denticulate forest (Md), Millettia laptobotrya forest (Ml), Musa acuminata forest (Ma) and Dendrocalamus membranaceae forest (Dm) in Xishuangbanna showed that Acari, Hymenoptera (ant) and Collembola were the dominant groups of soil arthropods on all study sites, but their proportions differed in different forests. For the common and rare groups of soil arthropods, there were some differences in four forests. We found fewer taxonomic groups (number of order), individuals and DG diversity index of soil arthropod communities in Dm secondary forest, as compared to another three forest types. There was no significant difference in number of groups and individuals and DG diversity index of soil arthropods among Md, Ml and Ma. The taxonomic diversity and population of soil arthropods were higher in top soil (0-5 cm) than in deeper layers. The research indicated that the dynamics of soil arthropods was correlated with the fluctuation of temperature and rainfall in this area. In general, the groups, populations and DG diversity index of soil arthropod communities were higher in dry season or early rainy season than in middle rainy season. There were some differences in the seasonal variation of soil arthropod communities in different type forests, which was primarily related to precipitation, temperature, litter quantity and quality, and biology of different soil arthropods. Apparently, food, habitation and disturb also have effects on the seasonal variation of soil arthropod communities in different forests.