黄土高原表土有机碳和无机碳的空间分布及碳储量

Storage and spatial distribution of organic and inorganic carbon in the topsoil of Loess Plateau

选取位于干旱-半干旱区的黄土高原陕西境内表土样品为研究对象,对其有机碳(Soil organiccarbon,简称SOC)和无机碳的空间分布及陕西省碳储量进行初步研究。结果表明:黄土高原陕西境内有机碳和无机碳的平均值分别为5.41g/kg和17.04g/kg,有机碳的空间分布是自北向南呈现出增加的趋势,这也与所处环境相符,无机碳的空间分布特征沿着纬度呈现自北向南逐渐增加的趋势,特别是北纬36o以北;将每一区域内CaCO3含量的平均值与相对区域的降雨量和温度分别进行一元线性拟合,其拟合系数分别为R=0.338和0.182,碳酸盐含量与降雨量和温度的相关性并不显著。陕西省表土有机碳和无机碳储量分别为0.272Pg和0.856Pg,无机碳储量远大于有机碳储量,这与其所处干旱环境有关。

Through selecting the surfer soil samplings in Loess Plateau in Shaanxi Province, we analyzed the spa- tial distribution of the contents organic carbon and inorganic carbon and carbon storage in Shaanxi Province. The results showed that the average concentration of organic carbon and inorganic carbon were 5.41g/kg and 17.04g/ kg, the spatial distribution of organic carbon was showing an increasing trend from north to south, consistent with its environment, while the spatial distribution of inorganic carbon also presented the growing trend from north to south along the latitude, especially north of latitude 360 ; Using the CaCO3 contents and regional average rainfall and temperature to conduct a linear fitting, we found the fitting coefficients were only 0.367 and 0.297, respec- tively, correlation between carbonate content and rainfall and temperature were not significant. The storage of or- ganic carbon （0.278 Pg） was larger than the inorganic carbon （0.877Pg） in surface soil in Shaanxi Province. The reason for that phenomenon was related to the arid environment.