Nutrient advantage of karst peaks cluster depressions and plant diversity in response

We found that: (1) Shrubland vegetation exhibits significantly higher soil organic carbon (SOC) content than grasslands and forests, indicating greater carbon sequestration potential; total nitrogen (TN) was the primary limiting nutrient. (2) Shrubland communities reached peak values for Margalef, Shannon-Wiener, and Pielou indices, with SOC showing a significant positive correlation with the Pielou index. (3) Soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) content were core factors regulating plant species diversity. The soil nitrogen-to-phosphorus (N:P) ratio was a key regulator, significantly influencing species composition and spatial distribution. (4) The PLS-SEM model further quantified the interaction pathways among these factors, providing a theoretical basis for optimizing vegetation diversity and managing soil nutrients in regional rock desertification control.