Beta diversity of grasshoppers and predatory beetles across steppes is closely associated with altitude and average annual precipitation in Ningxia, northwest China

Beta diversity analysis was conducted to identify factors affecting the beta diversity patterns of grasshoppers and predatory beetles in steppes and the primary environmental drivers of these patterns in Ningxia, northwest China. Data on the insects and environment of 42 steppe monitoring areas in Ningxia were analyzed. A total of 4335 insects of 50 species were captured from 42 monitoring areas, including 743 grasshoppers and 3592 predatory beetles belonging to 27 and 23 species, respectively. Non-metric multidimensional scale (NMDS) indicated a high similarity in the grasshopper communities between temperate meadow steppe (TMS) and temperate steppe (TS). Additionally, there was a high similarity among the predatory beetle communities between temperate desert steppe (TDS) and TS. Redundancy analysis (RDA) showed altitude (AL) and average annual precipitation (PP) could explain the interaction between insects and the environment to a large extent. Among the four steppes, the beta diversity of grasshoppers was predominantly driven by the richness component. In TMS and temperate steppe desertification (TSD), the beta diversity of predatory beetles was dominated by the richness component, whereas in TS and TDS, the beta diversity of predatory beetles was dominated by the turnover component. Mantel test indicated that a difference in the beta diversity of the grasshoppers and predatory beetles correlated positively with AL (P