The Biomass And Soil Carbon And Nitrogen Of L.Chinensis Grassland&S.Grandis Grassland Under Different Ways Of Using In Xilingol

This paper adopts the typical steppes in Xilinguole(L.chinensis grassland&S.grandis grassland)as the object,analyzes the above-ground biomass,underground biomass,soil organic carbon,total nitrogen characteristics and the correlation among these factors in different utilization modes(mowing and grazing).The main results are as follows:1.In the L.chinensis grassland,underground biomass is remarkably correlated with aboveground biomass,soil organic carbon density,and soil total nitrogen density in the mowing mode(underground biomass is 1052.24-2907.61 g/m2 and aboveground biomass is 100.37-381.94 g/m2).However,there is no significant correlation in the grazing mode(underground biomass is 801.11-1942.26 g/m2 and aboveground biomass is 42.87-108.74 g/m2).2.In the Stipa grassland,underground biomass is 966.89-1724.27 g/m2 and aboveground biomass is 144.35-224.86g/m2 in mowing mode.And aboveground biomass is 85.8-367.34 g/m2 in grazing mode.Underground biomass is not correlated with aboveground biomass,soil organic carbon density,and soil total nitrogen density in the mowing and grazing mode.There is significantly negative correlation between the underground biomass and soil bulk density in the mowing mode.3.In the L.chinensis grassland and Stipa grassland,soil organic carbon density,soil total nitrogen density and carbon nitrogen ratio have obviously shown the vertical distribution pattern in mowing and grazing modes.4.Under both modes(same grassland in different land-use,and different grasslands in the same landuse),soil organic carbon density,soil nitrogen density and soil carbon nitrogen ratio in each layer are significantly correlated.