Effects of climatic factors on vegetation diversity
The linear fitting plot (Figure 1A-F) reflects the trend of vegetation diversity index with temperature increase from control group (0) to high grazing intensity (3). In the dry season, the three vegetation diversity almost had no significant change with the increase of DT at medium and low grazing intensity (0, 1, and 2). At high grazing intensity (3, 4), the three indices were positively correlated with DT. In the rainy season, the three indexes of the control group (0) were negatively correlated with RT. In the low and high grazing intensity (1 and 4) groups, Simpson and Shannon indices had no significant change with the increase of RT, while Pielou index was negatively correlated with RT. Under moderate grazing intensity (2, 3), the three diversity indices were positively correlated with RT. The linear fitting plot (Figure 1G-L) analysis from the control group (0) to the high grazing intensity (3) group showed that the vegetation diversity index in the rainy season changed from an upward trend to a downward trend with the increase of RP. In the high grazing intensity (3) group, the diversity index was inversely proportional to precipitation in both dry and rainy seasons, and the variation trend was different from that under other grazing pressures. In the dry season, when the grazing intensity was 0, 1, 2, and 4, the variation range of diversity index with the increase of DP was small. In the rainy season, at low grazing intensity (0, 1), the three diversity indexes were positively correlated with RP, but at medium and high grazing intensity (2, 3), the three diversity indexes decreased with the increase of RP.