Grazing disturbance is one of main factors affecting species diversity of grassland plant communities. The species diversity was studied along grazing disturbance gradient of alpine grassland in the Eastern Qilian Mountains. The results showed that the grazing disturbed pastureland environment due to gnawing and treading of livestock, which changed plant species composition, population dominance and variety of community types,and then caused the changes of species diversity. As a consequence, the species richness of different communities were gradually lowered with the aggravating of grazing intensity. The species evenness and diversity indices reached the highest in heavy degradation or moderate degradation stages,and slightly increased again in over degradation stages and were related to the species evenness increases of the different communities. Life form also manifested some obvious changes along grazing disturbance gradient. Grazing disturbance was a common phenomenon, and also was the external driving function for the grassland ecosystem as it pushed forward the evolution and development of grassland ecosystem. Grazing disturbance had positive or negative effects on vegetation and was sometimes helpful for species diversity maintenance and conservation.
Journal of Gansu Agricultural University
Eastern Qilian Mountains