Effects Of Grassland Biodiversity And Environmental Factors On Community Productivity In Inner Mongolia

Global environmental change and loss of diversity make biodiversity and ecosystem function become a research hotspot,and productivity as one of the important ecosystem functions has attracted much attention.Inner Mongolia natural grassland has important ecological value,economic value and cultural value,but in recent years,due to climate change and human disturbance,the diversity and productivity are reduced,and the degraded area is increasing,which threatens the ecological security of north China.This study covers the three grassland of the grasslands of Inner Mongolia as the research object,using the community investigation,correlation analysis,variance decomposition,to set up the methods of structural equation model,explore the relationship between the Inner Mongolia grassland diversity and community productivity,and analyzed the environmental factors in Inner Mongolia steppe community productivity of direct effect and indirect effect.The main conclusions are as follows:1.There are certain differences in the community productivity among the three grassland sub-regions in Inner Mongolia.The community productivity of typical grassland and meadow grassland was significantly higher than that of desert grassland.2.There was a significant positive correlation between diversity and community productivity in Inner Mongolia grassland and its three sub-regions,but there were still differences.The community productivity of Inner Mongolia grassland was significantly correlated with species diversity,functional diversity and functional dominance indexes.Community productivity of desert grassland was significantly correlated with species richness and Rao's secondary entropy coefficient and functional dominance index.The community productivity of typical grassland and meadow grassland was only significantly correlated with functional dominance index.3.In Inner Mongolia grassland and its three grassland sub-regions,the explanation rate of diversity to productivity is the highest compared with climate and soil factors.Moreover,functional dominance is the most closely related to productivity,supporting the dominance of selection effect.In addition,the coupling effect of climate,soil and diversity is the strongest on the community productivity of Inner Mongolia grassland.The community productivity of desert steppe and typical steppe was strongly affected by diversity alone.The coupling effect of diversity and soil on community productivity was strongest in meadow steppe.4.Inner Mongolia grassland community productivity is regulated by both diversity and environmental factors.Climate and soil nutrients act on productivity directly and indirectly through diversity(mainly functional dominance).5.Inner Mongolia grassland community productivity is mainly affected by indirect effects of climate and direct and indirect effects of soil.The community productivity of desert steppe is mainly affected by the indirect effects of precipitation and temperature and the direct effects of soil nutrients.The productivity of typical grassland communities is mainly affected by the direct and indirect effects of annual average precipitation.The community productivity of meadow steppe is mainly affected by the direct and indirect effects of soil nutrients and the indirect effects of annual average temperature.