Plant community characteristics of grazing grassland in a deer farm in summer

In the summer pasture in the middle section of the northern slope of Qilian Mountain, the species diversity, functional group diversity, height, crown width and important values of alpine meadow and alpine shrub community under different topographical and different grazing intensities were analyzed. We found that: 1) with the increase in grazing intensity, the total species number was the highest under grazing, which is consistent with the " moderate disturbance hypothesis”. Under ‘shady slope’ conditions, the community functional diversity of light and moderate grazing was significantly higher than that of heavy grazing (P < 0.05). 2) The alpha diversity index was almost greatest in moderate grazing and the lowest in heavy grazing conditions of different topography. Under different grazing intensities, the valley had the highest species richness but the lowest Shannon-Wiener diversity index. 3) The plant height, crown width and important value of legume in light grazing on shady slope were the largest, the important values of Cyperaceae in valley and sunny slope increased with the increase of grazing intensity, the contrary in shady slope; the important value of Gramineae was the highest in middle grazing. The important value of Edible broadleaf increased with the increase of grazing intensity, and reached the maximum in the valley; the important value of Undesirable plant increased with the increase of grazing intensity, and there was the maximum value on the sunny slope.