Grasslands in the Qinghai–Tibet Plateau play an important role in preserving ecological security and high biodiversity in this region.However,the distribution of the composition and structure of plant community and t...Grasslands in the Qinghai–Tibet Plateau play an important role in preserving ecological security and high biodiversity in this region.However,the distribution of the composition and structure of plant community and the mechanism by which it maintains itself in this region are still poorly understood.Here,we designed 195 grassland plots in 39 grassland sites along an approximately 1700 m elevation gradient on the Northeastern Qinghai–Tibet Plateau.We found that the grassland community height decreased significantly with increasing elevation,whereas community coverage did not significantly change.With increasing elevation,plant species richness(αdiversity)increased significantly,but the community variability(βdiversity)decreased significantly.The constrained clustering analysis suggested that theα-andβ-diversity in the grasslands transformed gradually with elevation,and that three discontinuous points(based on community structure)were observed at elevation of 3640,4252 and 4333 m.Structural equation modeling(SEM)indicated that the increase in precipitation and the decrease in temperature significantly positively influencedαdiversity,which was negatively correlated withβdiversity.These results demonstrate a quantitative-to-qualitative change in the community composition and structure along this elevational gradient on the Qinghai–Tibet Plateau.展开更多
基金National Natural Science Foundation of China(31901172)Science and Technology Project of Qinghai Provincial Department of Transportation(2019-07).
文摘Grasslands in the Qinghai–Tibet Plateau play an important role in preserving ecological security and high biodiversity in this region.However,the distribution of the composition and structure of plant community and the mechanism by which it maintains itself in this region are still poorly understood.Here,we designed 195 grassland plots in 39 grassland sites along an approximately 1700 m elevation gradient on the Northeastern Qinghai–Tibet Plateau.We found that the grassland community height decreased significantly with increasing elevation,whereas community coverage did not significantly change.With increasing elevation,plant species richness(αdiversity)increased significantly,but the community variability(βdiversity)decreased significantly.The constrained clustering analysis suggested that theα-andβ-diversity in the grasslands transformed gradually with elevation,and that three discontinuous points(based on community structure)were observed at elevation of 3640,4252 and 4333 m.Structural equation modeling(SEM)indicated that the increase in precipitation and the decrease in temperature significantly positively influencedαdiversity,which was negatively correlated withβdiversity.These results demonstrate a quantitative-to-qualitative change in the community composition and structure along this elevational gradient on the Qinghai–Tibet Plateau.
