[Community structure of soil fauna under different tree species in subtropical forests]

Soil fauna play an important role in key functions of ecosystem such as material cycling. Litter quality and microenvironment of different tree species may regulate soil fauna community structure. In this study, we investigated soil fauna community structure, the differences of taxonomic and functional groups, and the regulatory factors under eight dominant tree species in August 2022. We captured 567 soil fauna (except for termites and ants), belonging to 3 phyla, 10 classes, 26 orders, and 99 families, with Achipteriidae, Trygoniidae, Poduridae, and Isotomidae as the dominant species. Tree species significantly affected soil fauna abundance, following an order: Michelia macclurei > Elaeocarpus decipiens > Castanopsis carlesii > Cunninghamia lanceolata > Lindera communis > Schima superba > Pinus massoniana > Liquidambar formosana. However, the richness, evenness, and diversity of soil fauna under different tree species were significantly different. Richness and diversity of M. macclurei, C. lanceolatas soil fauna were relatively high, while L. formosana, C. carlesii were relatively low. The evenness of meso-microfauna of L. formosana was the highest, which was significantly higher than that of M. macclureis and E. decipiens. The evenness of macrofauna and total soil fauna was not significantly different among the eight tree species. In addition, the abundance of omnivores and herbivores soil fauna was relatively high under M. macclurei, but relatively low under E. decipiens. The abundance of saprophages and predators soil fauna of E. decipiens, M. macclurei was higher than L. formosana, while saprophages was mainly meso-microfauna. Results of redundancy analysis showed that litter N, C:N, and K were the main factors affecting soil fauna community structure. The results indicated that the tree species with thicker litter layer and higher N and K contents may be conducive to enhancing the diversity of soil fauna community and affecting the distribution of different functional groups, thus contributing to the maintenance of forest biodiversity.