文摘

Background and aims Legumes play significant roles in improving soil fertility and are commonly used to improve net primary productivity (NPP). However, the relationship between legumes and soil food web conditions in forest ecosystems is poorly known. The objective of this work was to address this problem. Methods A shrub legume species, Cassia alata, was planted to the understory layers of mixed-canopy tree plantations in southern China. The effects of legume addition on soil physico-chemical properties and soil nematode community were measured. Results Legume addition significantly increased soil total nitrogen and tended to increase soil water content and organic carbon at two soil depths both during wet and dry seasons. Legume addition increased the maturity indices and structure index of soil nematodes, which indicated that the presence of legumes enhanced the structure of soil food web. Redundancy analysis revealed that soil physico-chemical properties can explain up to 19.2?% of total variance of soil nematode community represented by functional guilds. Conclusions Overall, there are significant interactions between legume and soil properties (both physico-chemical and biological properties); and the presence of legumes increases the soil nitrogen and organic contents and remarkably enhances the structure and complexity of the soil food web (i.e., more trophic links and multi-trophic interactions occured). Our findings could provide a better understanding of plant-soil interactions, particularly, the legume-soil interactions.