| The model about net ecosystem production applied remote sensing (NEPARS) was build here based on Biome-BGC and BEPS model. The model was applied to estimate carbon budget at different spatial scale: the Northeastern China and the main land of China. At last, author introduced the methodology on uncertainty analysis. And two kinds of model was comparedFirstly, the NEPARS model is characterized as follow: (1) the evapotranspiration model was modified with a double source model from the evaporation and transpiration sub-model in BEPS. In the double source model here, net radiance was divided into two parts: net radiance absorbed by vegetation and the one absorbed by soil, based on which the evapotranspiration was estimated. (2) An experiment was designed for the feasibility to estimate soil respiration from inferred temperature, which will improve the observation of soil respiration on large spatial scale. The result show there is significant correlation between soil respiration and inferred temperature. (3) Soil respiration well modeled with soil or air temperature and soil water, which was applied in this research after its Q10 was parameterized with the data from reference about soil respiration of Chinese terrestrial. (4) Except meteorological data as input, the MODIS data was used to drive the model. (5) Assessment to remote sensing data was emphasized, and the Chinese land cover classification and LAI were validated. (6) The other parameters were regulated with local research.According to the research for Northeastern China and whole China, some interesting conclusions were drawn out as follow.(1) Ecosystem evapotranspiration: the vegetation transpiration averagely is 132.86 (?5.03) mm, and maximum 284.83mm, while soil evaporation is 140.72mm and maximum 600 mm. the ratio of evapotranspiration to annually total precipitation is 71.51%. It is in a reasonable range according to reference.(2) Net Primary Production (NPP): The NPP of Northeastern China is 276.41 ( ?64.89) gCm'V1, maximum 862.85 gCm'V, which is better fitted with ground data from the Fourth China Forestry Survey. For whole China terrestrial, its NPP is 337.70 ( ?35.04) gCm'V1, rangedfrom 0 to 2987.19 gCm'V, from which the total NPP annually may be estimate as 3.249 PgCa"1. Compared with reference data, the result is less. However, the spatial and temporal pattern and its driven factors can be described. The significant correlation appeared between NPP and LAI, land cover class, temperature, and precipitation (p<0.001). And for NPP accumulation, LAI is main factor than temperature and precipitation.3) Soil Respiration (Rh): The soil respiration of Northeastern China is 250.57 ( ?174.55) gC m~2 a"1, maximum663.42 gC m"2 a"', while the one of whole China is 79.39 gCm'V1, and total carbon release from soil is 0.752 PgCyr"1.4) Net Ecosystem Production (NEP): The NEP of Northeastern China is + 25.83gCm"V and total carbon absorbed from atmosphere is 0.036PgCyr"', which is about 14.4% NEP in Amazonian ecosystems. On local spatial scale, The spatial pattern show that farm land, more disturbed by human, is carbon source, while natural forestry-, little disturbed is carbon sink. Of course, it needs more research to validate the conclusion. The NEP of whole China is 259.08 +289.7 lgCm~2yr~, which show whole terrestrial in China is carbon sink, and annually absorbed 2.45GPgyr"' carbon from atmosphere.5) NEP showed apparently spatial and temporal pattern. On season dynamic, vegetation begin to grow from the 97th day of year (DOY) and almost stop to the 289th DOY. Growth period is about 192 days. In grow season, the maximum value appeared about the 209th DOY. Temperature is dominant factor for carbon absorption and is quantitative with standard regression coefficient between NEP and temperature and precipitation. The effect of temperature is 1.92 to 20.67 times of that of precipitation.6) Uncertainty and model compare: The some methodologies was introduced firstly. Then model structure and modeling result were compared. On the whole, NEPARS m...
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