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.