Effects of grazing and rainy season precipitation on plant
species composition
In the surveyed areas, Gramineae is the most dominant species. The
results of contour line (Figure 7) showed that the coverage of grasses
did not have an obvious relationship with the precipitation in the rainy
season, but changed significantly with the increase of grazing
intensity, indicating that grazing intensity was an important factor
affecting the dominance of grasses. Gramineae showed greater coverage at
low grazing intensities, but at high grazing intensities, the coverage
of grasses decreased sharply or even disappeared. In the rainy season,
HL and DL, which has a large precipitation, the advantages of the grass
family have increased rapidly with the intensity of the grazing. Grazing
intensity and rainfall in rainy season were important indexes affecting
plant height. The grazing intensity was less than 3, and the coverage of
low-height plants increased with the increase of precipitation in the
rainy season, and reached the maximum when the precipitation was greater
than 280mm in the high rainy season. In high grazing intensity, the
coverage of plants with low plant height decreased with the increase of
rainy season precipitation (Figure 7). The trend of coverage of tall
plants was opposite to that of short individual plants.