The Effects Of Warming And Precipitation Increasing On Root Production And Turnover Rate Of Stipa Breviflora Community

Climate change has led to a gradual increase temperature,changes in precipitation patterns,and frequent occurrence of extreme weather.Desert grasslands play an extremely important role as a transition zone between grasslands and deserts,and as an important part of the carbon pool of terrestrial ecosystems,their carbon balance is an important part of global climate change.In this study,the Stipa breviflora community in Inner Mongolia desert grassland was used as the research object.By analyzing the changes of plant community characteristics,community root length productivity,and community root turnover rate under different gradients of warming(0℃,2℃,4℃),different gradients of precipitation(0%,25%,50%)and their interactions,the following results were obtained in a 2-year experiment:(1)Warming the height of perennial bunch grasses and Perennial forbs,while precipitation increasing had promoted the height of Perennial forbs and Annual and biennial,and suppressed perennial bunch grasses Shrubs and semi-shrub.(2)The coverage of perennial bunch grasses was significantly increased under the warming treatment(p<0.05),and the precipitation increasing enhanced the coverage of perennial bunch grasses and sub-shrub and semi-shrubs.(3)Repeated-measures ANOVA showed that the main effects of warming and precipitation increasing had no significant effect on the root length productivity of the community,while the interaction between warming and precipitation increasing had a significant effect(p<0.05).the root length productivity of the community increased significantly in 2019(p<0.05),but decreased significantly in 2020.Both warming and precipitation increased root length productivity of community in 0-10 cm and 10-20 cm soil layers.(4)Repeated-measures ANOVA showed that the main effect of warming and precipitation increasing had no significant effect on the root turnover rate of the community,but the interaction of warming and precipitation increasing can significantly increase the root turnover rate of the community(p<0.05).And it is significantly affected by soil layer(p<0.05)0-10 cm soil layer is greater than 10-20 cm soil layer.Warming and precipitation increasing increases significantly promoted root productivity and root turnover in desert steppe,but their effects were limited by interannual and soil layer.Among them,there were significant differences in root productivity and root turnover of plant communities in the dry year(2020)and the year with more precipitation(2019).The root productivity and root turnover of plant communities in the dry year were significantly lower than those in the wet year,indicating that annual precipitation is an important factor controlling root productivity and root turnover of desert grassland plant communities.