The Addition of an Invasive Plant Alters the Home-Field Advantage of Native Leaf Litter Decomposition

Forest litter can decompose faster at home sites than at guest sites (home-field advantage, HFA), yet few studies have focused on the response of the HFA of native plant decomposition to the presence of invasive plants. We loaded the dry leaves of native Neosinocalamus affinis (decomposition resistant) and Ficus virens (more easily decomposable) leaves into litterbags with and without invasive Alternanthera philoxeroides, and incubated these litterbags at N. affinis and F. virens sites at the edge of the forest. The results showed that positive HFA effects with litter mass loss were at least 1.32% faster at home sites than at guest sites. The addition of A. philoxeroides reduced the mean HFA of N. affinis litter and increased that of F. virens litter. The HFA index without A. philoxeroides was significantly higher than that with A. philoxeroides. Soil faunal abundance colonized at home sites was always higher than that colonized at guest sites. Compared with the F. virens site, the abundance of Collembola, Arachnida, Formicidae and Lepismatidae at the N. affinis site was significantly higher compared to the F. virens site, while the abundance of Isopoda, Oligochaeta, Nematoda and Dermaptera was significantly lower. Our results indicate that invasive plants may regulate HFA effects by promoting the decomposition of native plants and increasing fauna abundance. Particularly, soil fauna groups play a very important role in this process. Our findings help us to re-understand the role of invasive plants in material cycling and energy flow in the context of achieving carbon neutrality goals.