Three dominant shrubs drive soil nutrient cycling in the Mu Us Desert through the regulation of soil nematode trophic diversity

Drivers of soil nutrient cycling in a desert ecosystem are a central focus of ecological restoration research, yet the regulatory role of soil nematode communities in this process remains poorly understood. This study investigated three dominant shrublands in the Mu Us Desert: Artemisia ordosica, Caragana korshinskii, and Salix psammophila. We examined the relationships between plant functional traits and soil nematode community structure to elucidate the pathways through which shrubs drive nutrient cycling via modulating nematode diversity. The results showed that: (i) the trophic diversity of soil nematodes was significantly higher in the A. ordosica shrubland than in the C. korshinskii and S. psammophila shrublands; (ii) the nutrient cycling function was significantly enhanced in the A. ordosica shrubland compared to the other two shrublands; and (iii) A. ordosica promoted soil nematode trophic diversity synergistically through higher specific root length, lower root tissue density, and greater soil water content, thereby strengthening nutrient cycling function. This study provides deeper insights into the mechanisms of nutrient cycling across different shrublands in the Mu Us Desert from a soil nematode perspective, and it offers a scientific basis for a function-based species selection strategy in the ecological restoration of desertified regions.