| With the trend of global warming, the carbon dioxide emissions has become a hot issue of common concern in the world today.Grassland ecosystems as part of the land ecosystems system, is one important means of carbon sinks,so the ecological funtions of it becomes more prominent, and attracts more and more widespread attention. At present, the international community has used the carbon sink fuction of ecosystems to complete carbon trading all around the world,and maken it to be an effective way to reduce carbon emission. In this study,on the use of the Heihe River Basin in 2013 meteorological data, Terra/Modis NDVI data, and field sampling data, and adopting the methods of C-FIX model and mathematical statistics,different vegetation types NPP,vegetation carbon storage,and the amount of carbon carbon sequestration and oxygen release of grassland ecosystems in upstream of Heihe River basin have been analyzed and estimated in detail.Meanwhile, the soil organic carbon storage of all grassland vegetation types have been analyzed and estimated,using the actual measured soil organic carbon data.Finally, the carbon storage and value of grassland ecosystem in Heihe River basin upstream were evaluated. The following conclusions are concluded:(1) The annual averge of cumulative amount per unit area of NPP was 104.41gC·m-2·a-1 in 2013,and the total amount of it ranged from 0.001-453.969gC·m-2.There was a bigger heterogeneity among space distribution pattern of NPP, showed a decreasing trend from southeast to southwest on the whole for Heihe River basin upstream of grassland ecosystem in 2013.The types of grassland that per unit area vegetation NPP total cumulative amount from high to low were as follows:alpine meadow> Shrub grassland>alpine grass> desert grassland, NPP cumulative amount were 121.69gC·m-2,121.34 gC·m-2,111.87gC·m-2, and 62.73gC·m-2respectively.All types of grassland vegetation underground carbon density were lower alpine meadow 963.78 gC·m-2·a-1, shrub grassland 946.46 gC·m-2,alpine grass 475.44 gC·m-2,and desert grassland 494.94 gC·m-2 respectively. All grassland vegetation types total carbon storage amount in 2013 were as follows:alpine meadow was 12.2 ×106tC, alpine grass was 4.69 x 106tC, Shrub land was 2.52 x 106tC,and desert grassland was 0.6 x 106tC, consistent with the annual NPP accumulated amount. Heihe River basin upstream of grassland vegetation NPP Value and vegetation carbon storage spatial distribution pattern were consistent with the NPP spatial pattern of substance in 2013, showing that space value still gradually decreased from east to west.Grassland vegetation carbon total storage was 46.38×108yuan, the total value of NPP was 6.06×108yuan, the total value of underground sequestration of 40.32×108yuan.The annual average cumulative amount of all types of grassland vegetation NPP value ranged from145.42 to 282.1 yuan·hm-2,and the average value was 242.04 yuan·hm-2;The annual averge cumulative amount of carbon underground ranged from 1102.17 to 2234.24 yuan·hm-2,and the average value was 1669.46yuan·hm-2. The each unit area of grassland vegetation NPP Value were alpine meadow was 282.1 yuan·hm-2, Shrub land was 281.29 yuan·hm-2, alpine grass was 259.34 yuan·hm-2, desert grassland was 145.42 yuan·hm-2, respectively.(2) In the upstream of Heihe River,the material quantity that CO2 fixationed of the grassland ecosystem in 2013was 42.51×105t and quantity that O2 released was 31.30 ×105t.The unit area quality of fixed carbon dioxide and oxygen released of different grassland vegetation types from high to low were as follows:alpine meadow> Shrub land> alpine grass> desert grassland, and unit area quality of the fixed carbon dioxide respectively were:1.98t·hm-2,1.97 t·hm-2,1.82 t·hm-2,1.02 t·hm-2; O2 released of substance were:1.46 t·hm-2,1.45 t·hm-2,1.34 t·hm-2,and 0.75 t·hm-2.The total amount of CO2 fixation and O2 released of all grassland vegetation types respectively were:alpine meadow were 22.29 ×105t and 16.41 ×105t, alpine grass were 14.58×105tand 10.73× 105t, Shrub land were 4.66 ×105t and 3.43 ×105t, desert grassland were 1.09×105t and 0.81 ×105t.Total vaule that carbon dioxide fixed and oxygen released of grassland vegetation in2013 was 25.47 × 108 yuan, of which the value carbon dioxide fixed was 15.62 × 108 yuan, and that O2 released was 9.85 × 108 yuan. The total value of carbon dioxide fixed and oxygen released of all grassland vegetation types respectively were 13.32 × 108 yuan,8.71×108 yuan,2.79×108 yuan,and 0.65×108 yuan.(3) Organic carbon total storage amount of the soil,which depth was from 0 to 100cm, was 53.49×1010t, and the total value of that was 29.42×109yuan.And all types of grassland vegetation’s organic carbon total storage amount of the soil, which depth was from 0 to 20cm,was 17.57×1010t, and the total value of that was 9.86×109 yuan. Average content of grassland vegetation and soil organic carbon was from 10.89 to 77.65g·kg-1, which soil depth was from 0 to 100cm,as the depth increases, the average content decreases. The soil,which depth was from 0 to 100cm, organic carbon’s coefficient of variation was 10%～100%, belonging to moderate variability, and the average coefficient of variation was 78.01%. Average organic carbon content of soil,which depth was from 0 to 100cm,was 22.05kg·m-2,applying to all types of grassland vegetation cover.All grassland vegetation and soil organic carbon content which soil depth was 0～20cm were as follows:Shrub land was 8.76kg·m-2, alpine meadow was 8.06 kg·m-2, alpine grass was 7.49 kg·m-2, desert grassland was 4.25 kg·m-2;And that content which soil depth was 0～ 100cm were as follows:Shrub land was 30.57 kg·m-2, alpine meadow was 24.28 kg·m-2,alpine grass was 22.26 kg·m-2, and desert grassland was 11.11kg·m-2. The total carbon storage of all grassland vegetation in 2013 were as follows:alpine meadow was 27.29×1010t, alpine grass was 17.8×1010t, Shrub land was 7.21×1010t, desert grassland was 1.19 × 1010t; The total value of that were respectively as follows:alpine meadow was 15.01 x 109 yuan, alpine grass was 9.79 ×109 yuan, Shrub land was 3.96 ×109 yuan, desert grassland was 0.65x 109 yuan. Soil organic carbon storage amounts from high to low were as follows:alpine meadow>alpine grass> Shrub land> desert grassland.(4) In the upstream of Heihe River, the total value of carbon sinks of grassland ecosystem was 370.07×108yuan. The value of carbon sinks of all grassland vegetation types respectively were:alpine meadow was 189.67×108yuan, the alpine grass was 118.26 ×108yuan, shrub grassland was 48.22 ×108yuan, desert grassland was 13.92×108yuan, showing that the value of soil carbon storage amount> the value of grassland vegetation carbon storage amount> Value of carbon stored and oxygen released amount.
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