Effects of non-native tree plantations on soil microarthropods and their feeding activity on the Chinese Loess Plateau

Abstract

Afforestation with non-native tree species is regarded as a rapid management strategy to rehabilitate degraded ecosystems. Despite the well-documented effects of non-native forest plantations (NNFPs) on plant diversity, relatively few studies have explored the effects of NNFPs on soil fauna and ecosystem processes mediated by them. Soil microarthropods are key contributors to decomposition and soil biogeochemical cycling processes, and their feeding activity has been recognized as an important functional indicator in soil. Here, we investigated the soil microarthropod diversity (mites and springtails) and their feeding activity in non-native Robinia pseudoacacia (RP), Populus × canadensis (PC) and native Armeniaca sibirica (AS) forests on the Chinese Loess Plateau. We also investigated the soil properties and understory plant diversity to explore the potential links among these variables and feeding activity by using structural equation modeling (SEM). The abundance of soil microarthropods was significantly greater in the non-native RP and PC plantations than in the native AS plantations. The feeding activity in the RP and AS plantations was at a similar level to each other and was significantly lower than that in the PC plantations. Results from SEM showed that non-native PC rather than RP plantations significantly increased feeding activity by raising the abundance of mites and/or springtails. The results demonstrate that the effects of NNFPs on feeding activity depend on tree identity, and suggest that non-native PC rather than RP plantations contribute to enhancing soil ecosystem functioning, which provide guidance for non-native tree selection on the Loess Plateau.