伊犁昭苏草原黑钙土不同海拔高度土壤有机碳的垂直分布特征

The Vertical Distribution Characteristics of Ili Zhaosu Grassland Chernozem Soil Organic Carbon at Different Altitudes

【目的】以伊犁昭苏草原黑钙土为对象,研究分析草原黑钙土有机碳含量、储量及密度的垂直分布特征及空间变异性。【方法】采用重铬酸钾-外加热法,测定不同海拔高度0~100 cm土层土壤有机碳含量,研究土壤有机碳储量与密度等在不同海拔高度和土层厚度上的空间变异性。【结果】伊犁昭苏草原黑钙土有机碳含量、碳储量和碳密度不仅随着海拔高度的升高而降低,而且也随土层厚度的增加呈降低趋势。研究区100 cm处有机碳含量、储量和密度在海拔1 000~3 000 m分别为64.70~616.79 g/kg、4.49×10^(-8)~1.94×10^(-6)Pg/hm^2、3.26~194.27 kg/m^2。典型草原黑钙土土壤有机碳含量、储量和密度与海拔高度呈显著负相关(r=-0.92,-0.943,-0.95),与土层厚度呈极显著负相关(r=-0.989**,-0.968**,-0.966**)。【结论】伊犁昭苏草原黑钙土有机碳含量、储量与密度随着海拔高度的升高与剖面深度的增加而降低。

[ Objective ] This project aims to analyze the vertical distribution characteristics of Zhaosu grassland chernozem soil organic carbon content, carbon storage and density. [ Method] Using Potassium di- chromate external heating method to measure the soil organic carbon content in 0 - 100 cm soil depth at differ- ent altitudes and discuss their changes. [ Result] Results showed that Ill Zhaosu grassland chernozem organic carbon content, carbon storage, carbon density revealed a trend of decrease with the increase of altitudes and the soil depths. Organic carbon content, carbon storage and density of 100 em in the study area at the attitudes between 1,000 - 3,000 m were 64.70 - 616.78 g/kg, 4.49 × 10-5- 1.94 × 10-6 Pg/hm2 and 3.26 - 194.27 kg/m2, respectively. The typical grassland chernozem soil organic carbon content, carbon storage density and altitude were negatively correlated. （r = -0.92, -0.943, -0.95） and had significantly negative correlation with the soil layer thickness （r = -0. 989＊ ＊, -0. 968 ＊ ＊, -0. 966 ＊ ＊ ）. [ Conclusion] Ili Zhaosu grassland chernozem soil organic carbon content, carbon storage and carbon density decreased with the in- crease of altitudes and depths in the profiles.