The Dynamic Of Carbon Pool Of Tibet And Its Influence Factors

Land use/land cove change is one of the main driving forth of ecosystem carbon storage and sequestration.Tibet is located in the hinterland of the Qinghai-Tibet Plateau,is a kind of typical ecologically fragile and sensitive areas,and study the impact of climate change and land use / land cover change on carbon storage is important in environmental management.With the Land Cover data from MODIS MCD12Q1,the carbon storage and sequestration of Tibet is calculated by the InVEST toolset,considering the four carbon pool including the aboveground biomass,belowground biomass,dead wood,soil carbon,and quadrats data calibration of given the model parameters.The dynamic of carbon pool of Tibet and influence factors is analyzed in the period from 2001 to 2010,and the transfer of land cover types,the carbon density contributions to carbon storage were discussed mainly.The main conclusion lies in:1)The carbon storage increased 50 million t in Tibet from 2001 to 2010.Southeast Tibet and northwest Tibet experienced an large change in carbon storage with some areas increased while others decreased at the same time,the middle and northern Tibet was relatively stable.The carbon storage of the farming areas continued reduced 39 million t,the farming and pastoral areas' reduced 25 million t,yet the pastoral areas had an increase of 114 million t.The carbon density of water resource conservation areas and windbreak and sand fixation increased remarkable.According to the analysis of land use types,grassland was continued growing,forest and sparse vegetation was stable.Grassland carbon storage accounted for 57.1% and 62.1% in Tibet total carbon storage respectively in 2001 and 2010,forest carbon storage accounted for 11.8% and 11.1,sparsely vegetation carbon storage accounted for 20.1% and 19.2%.2)The land area of high carbon density increased more,such as Grassland,forest;the land area of low carbon density decreased more,for instance shrub,sparsely vegetation in Tibet from 2001 to 2010.Assuming carbon density constant,only the type of land cover change caused carbon storage increased 126 million t,contribution of land cover change to carbon storage was 269%.3)most of lands that carbon density decreased remarkable were the high carbon density land type,such as forest,and permanent wetlands.However,most of lands that carbon density increased were the low carbon density land,such as water,crop and sparsely vegetated.Assuming land cover keep constant,only the carbon density change caused carbon storage decreased 79 million t,contribution of carbon density change to carbon storage was-169%.