Relationship among species diversity, functional composition, and forage quality in typical alpine grassland of the Qilian Mountains

The relationship between forage quality and species diversity is an important basis for grass-livestock interactions. Additionally, it is also an important mechanism in grazing to stabilize the structure and function of grassland ecosystems. In this study, alpine typical grassland grazing by Cervus elaphus kansuensis in the Qilian Mountains was the research object, and the relationship among community species diversity, functional composition, and forage quality was analyzed. The results showed that: 1) the Pielou evenness index and biomass proportion of Cyperaceae were positively correlated with crude protein yield (P < 0.01), and the biomass proportion of forbs was negatively correlated with crude protein yield (P < 0.05). 2) the species richness and biomass proportion of forbs and inedible forages were positively correlated with forage water content (P < 0.001) and the Pielou evenness index and biomass proportion of Rosaceae were negatively correlated with forage water content (P < 0.001). 3) the biomass proportion of Cyperaceae and inedible forages contributed the most to crude protein yield and water content, which were 0.75 and 0.80, respectively. In summary, species diversity and functional composition are the main factors contributing to changes in forage quality. Grassland management should involve actively responding to potential changes in community structure and formulation of corresponding grazing management strategies to ensure efficient use of grassland resources.