The loss of plant species diversity dominated by temperature promotes local productivity in the steppe of eastern Inner Mongolia

In the semiarid grassland ecosystems of eastern Inner Mongolia, the interrelations among the species diversity of different plant communities, productivity, soil nutrients and climate were thoroughly studied through integrated approaches combined with the sample method, correlation analysis and structural equation modelling (SEM) model. The results show that the colonization of perennial grasses was promoted in the wetter and colder climate conditions. The productivity was determined by the perennial grasses, while species diversity was dominated by the perennial forbs. We obtained a U-shaped relationship between biomass and species diversity, which indicated two different strategies for the interaction between grassland biomass and diversity. In our study, air temperature and plant biomass were determined to be the main two indicators of plant species diversity variation. Meanwhile, distinct mutual constraints existed between the biomass of grassland dominant species and species diversity. Furthermore, soil nutrient conditions and climatic factors were found to jointly affect grassland productivity. This study will be helpful in providing deep insight into the dynamics of plant species diversity and the main interactive influencing factors in the semiarid steppe ecosystem and will provide a scientific basis for the maintenance of plant diversity and ecosystem functions in this region.