Effect of different land use on the biomass and organic carbon of plant communities in alpine meadow

As one of the major ecosystems in the Tibetan Plateau,alpine meadow has been playing an important role in ecological equilibrium.With the population growth,alpine meadow has been cultivated to meet the demands for foods and benefits.In order to study the effect of land use change on the biomass and amounts of fixed-carbon of vegetation,alpine meadow(Kobresia humilis),the croplands and artificial grasslands formed by cultivating alpine meadow were selected in the Haibei research station,Chinese Academy of Science.The results indicated that the aboveground biomass rates varied among alpine meadow,croplands and artificial grasslands with an order of artificial grasslandcroplandsalpine meadow(P0.01),respectively,the rate was 11.83,9.78,4.36 t/hm2.The vertical distribution of belowground biomass displayed reverse pyramidal models in alpine meadow,croplands and artificial grasslands respectively.In 0~40 cm soil depth,the belowground biomass ranged with an order alpine meadowartificial grasslandcroplands(P0.01),the rate was 15.74,5.61,1.24 t/hm2.With the change of alpine meadow land use,the amounts of fixed-carbon of vegetation varied with the rank of alpine meadowartificial grasslandcroplands(P0.05),respectively,the rate was 7.63,6.81,4.51 t/hm2.