[Community structure of soil mites under Quercus variabilis forests in small watershed of karst area, Guizhou, China.]

To analyze the differences of community structure of soil mites between the rocky desertification environment and karst beech forests, we investigated the soil mites of Quercus variabilis forest in the Chaoying small watershed of Guizhou Province. Soil mites from 83 genera, 54 families, and 3 orders were collected in the four investigations of 2014. We analyzed the differences of genus numbers, individual numbers, individual density, Shannon diversity index (H), Margalef richness index (SR), Pielou evenness index (J), maturity index (MI) of predatory soil mites (Mesostigmata: Gamasina), community structure of the oribatid mites (MGP) and nutritional structure of mite. Results showed that Oribatida was dominant in taxonomic richness and individual abundance. Abundant genus, high individual density and diversity of soil mites were found in summer and autumn, and higher individual abundance was found in spring and autumn. Soil mites showed surface-aggregation in their distribution. Most predatory mites were K-selected in summer and r-selected in other seasons. The ecological groups of the oribatid mites were mainly P-type and O-type. Hypochthonius, Allobelba and Zygoribatula constituted the nutrient function group of the soil mites. There were significant differences in the main groups of soil mites in the beech forest and other forest types. Among all the groups, Parholaspididae, Laelapidae, Oppiidae and Haplozetidae with abundant genera composition, Multioppia, Parholaspulus, Scheloribates and Haplozetes with predominance could be used as a biological indicator for the soil environment in beech forests.