Abstract: We investigated the effects of different grassland utilization strategies on soil nematode community structure of degraded Sophora alopecuroides dominated grasslands, by analyzing the community structure characteristics, ecological function indices, community composition, and their relationships with soil physical and chemical properties of soil nematodes. The study aimed to provide a scientific foundation for the ecological restoration of degraded Sophora alopecuroides dominated grassland. The results showed that the abundance of soil nematodes differed significantly among treatments (P<0.05). The rank of different grassland utilization strategies with respect to soil nematode density was as follows: fencing and mowing > grazing and mowing > exclusion fencing > free grazing. Plant parasitic nematodes were the dominant trophic group, and Paratylenchus was the dominant genus across all treatments. The whole nematode community exhibited an r-strategy life history. Compared to grazing plots, fencing plots had higher nematode diversity index, richness index, and evenness index. The Wasilewska index was less than 1, and the nematode channel ratio was higher than 0.5, indicating that soil nematode community was dominated by bacterivores. The nematode total metabolic footprint was significantly higher under fencing than under grazing, indicating faster metabolic processes. Faunal analysis results suggested a low level of soil nutrient enrichment and an unstable food web. Soil organic carbon, total nitrogen, nitrate nitrogen, and ammonium significantly influenced soil nematode community composition. The soil nematode community structure differed significantly among different grassland utilization strategies. The abundance of nematodes under mowing was higher than that under fencing, while the abundance of nematodes under grazing and mowing was higher than that under free grazing. Moreover, the combined metabolic activity of the nematodes was enhanced. Compared to grazing conditions, the degree of grassland degradation was lighter under fencing conditions.

Key words: soil nematodes, community structure, grassland utilization method, degraded grassland, Sophora alopecuroides