Associations between grasshoppers and environmental factors analyzed using detrended correspondence analysis and canonical correspondence analysis in Bortala Mongol Autonomous Prefecture, Xinjiang

Grasshoppers are important pests of natural grasslands in Xinjiang and their abundance is influenced by various environmental factors such as vegetation cover, vegetation species composition, and elevation. A comprehensive study of vegetation characteristics and environmental factors can provide insight into the adaptations of the grasshoppers and their habitats. Based on the distribution and composition of the dominant grasshopper in seven grassland types in Bozhou, we analyzed the relationship between grasshopper abundance and ten ecological factors. Detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) were performed to clarify the influence of vegetation (community characteristics, cover, and composition of dominant vegetation species) and elevation on grasshopper abundance. The results showed that elevation, vegetation cover, Shannon-Wiener diversity index, and Simpson dominance index of vegetation communities significantly differed among grassland types (P < 0.05). The dominance of Leguminosae did not differ significantly (P > 0.05) among lowland meadows, temperate deserts, temperate steppe deserts, temperate desert grasslands, temperate grasslands, temperate meadow grasslands, and montane meadows, whereas Compositae, Gramineae, Chenopodiaceae, and other families showed some differences in dominance among grassland types. The dominance of Compositae, Gramineae, Chenopodiaceae, and other families differed significantly (P < 0.05) among grassland types. The CCA-based analysis showed that elevation and cover had the strongest effect on grasshopper abundance, whereas plant community evenness showed the weakest effect on grasshopper abundance. Based on the DCA analysis, 25 grasshopper species were divided into six communities (communities Ⅰ–Ⅵ), among which communities I and II were mainly distributed in desert grassland types, and their abundance was influenced by the dominance of Quinoa; communities Ⅲ–Ⅴ were mainly distributed in grassland meadows and their abundance was influenced by the dominance of Leguminosae and Gramineae; community Ⅵ was mainly distributed in lowland meadows. The elevation is an important factor influencing grasshopper abundance, and the distribution of the six grasshopper communities was related to the grassland type.