腾格里沙漠东南缘固沙区深层土壤无机碳密度及其垂直分布特征

Soil Inorganic Carbon Density and Distribution Characteristics in Sand-Fixed Dunes in the Tengger Desert,Northern China

对腾格里沙漠东南缘天然植被区、流沙区以及1964,1981,1990年建立的人工固沙植被区0-3.0m剖面土壤和根鞘中无机碳含量及其分布特征进行调查。结果表明,天然植被区和固沙区总无机碳密度高于流沙区,分别为15.2,10.7,9.38kg/m2;根鞘中无机碳含量占土壤总无机碳含量的20%以上。不同年代固沙区和流沙区无机碳含量垂直分布特征均表现为表层显著高于中层和深层无机碳储量;根鞘中无机碳含量表现为逐渐递增的趋势,1.5-3.0m土层根鞘中无机碳含量最高,为0.3～1.4kg/m3。植物恢复有利于土壤无机碳的固存,能够显著提高土壤中总无机碳含量;根鞘中的无机碳是干旱半干旱区土壤无机碳的重要组成部分,在估算土壤总无机碳储量时应给予充分考虑。

A quantitative survey of total soil inorganic carbon and distribution characteristics in 0-3.0 m depth was carried out in natural vegetation area,sand-fixed and sand dunes in the Tengger desert,northern China.The results showed that total soil inorganic carbon density on natural vegetarian area and sand-fixed dunes was higher than sand dunes,the value was 15.21,10.65,9.38 kg/m2,respectively;root channel inorganic carbon content accounted for 20% of the total soil inorganic carbon content.Soil inorganic carbon vertical distribution characteristics were showed that surface layer was significantly higher than middle and deep soil layer,on the contrary,root channel inorganic carbon increased with soil depth,the highest value occurred in 1.5-3.0 m,was 0.3~1.4 kg/m3.The results indicated that,on temporal and spatial scale,sand-fixed dunes were more conducive to carbon sequestration,and significantly increased soil inorganic carbon stock;root channel inorganic carbon was an important component of total soil inorganic carbon in arid and semi-arid regions and should be giving full consideration when estimating total soil inorganic carbon stock.