Relationship between soil moisture and biomass in grazing land of wapiti on an alpine steppe

An experiment was performed in winter and spring-autumn pastures of Gansu wapiti in Gansu Province, Sunan Yugu National Autonomous County, using six different grazing gradient plots. The wild fixed-point sampling observation method was used to study the interaction of grassland soil moisture with biomass under the influence of different grazing gradients. The results showed that there were significant negative correlations between soil moisture and grazing rate in both winter and spring-autumn pastures in the Qilian Mountains (P < 0.01). There was a significant positive correlation between winter pasture biomass and soil moisture (P < 0.05). There was a significant positive correlation (P < 0.01) between underground biomass and soil moisture in spring-autumn pasture. A structural model showed that soil moisture of winter pastures had the greatest effect on aboveground biomass, and that soil moisture had a significant indirect effect on the root and shoot ratio through aboveground biomass. The underground biomass of spring-autumn pasture had the greatest effect on the root and shoot ratio, and soil moisture had a significant indirect effect on root and shoot ratio through underground biomass.