Figure 2 Linear fitting plots of vegetation diversity index and grazing gradient in different locations. A, C, and E are the linear fitting plots of Simpson, Shannon, Pielou index and grazing gradient in the dry season, and B, D, and F are the linear fitting plots of Simpson, Shannon, Pielou index and grazing gradient in the rainy season.
Interaction of grazing and climatic factors on vegetation diversity
Axis 1 in the NMDS figure represents the climate gradient and axis 2 represents the grazing gradient. Plant community composition was significantly different under different grazing gradients. Vegetation composition of grazing gradient 1 was mainly concentrated in the first and second quadrants in different research sites, and mainly distributed along axis 1. Grazing gradients 2-4 were mainly distributed along axis 2, concentrated in the third and fourth quadrants. Compared with the rainy season, the plant community composition under different grazing gradients at different study sites was more similar in the dry season. In the dry season, the species composition of WA (DT=5.77℃, RT=9.94℃, DP=40.1mm, RP=104.5mm) was significantly different from that of other sites, and the species composition of other sites showed high similarity. However, on the whole, the differences in species composition under the grazing gradient in the dry season were significantly lower than those in the rainy season (Figure 4).