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选择腾格里沙漠东南缘沙坡头地区不同年代建立的人工固沙林(1964、1981、1990年)及临近的流动沙丘,对0~3.0m剖面上的土壤进行取样和分析,以探讨固沙植被的建立和发展对土壤碳(有机碳和无机碳)分布的影响及其与土壤属性的关系。结果表明:在流动沙丘建立人工固沙植被近50年后,表层(0~0.1m)土壤有机碳和无机碳含量均明显增加,土壤有机碳含量为1.95g·kg~(-1),是流动沙丘的6.67倍,无机碳含量为4.19g·kg~(-1),是流动沙丘的1.46倍。将土壤剖面划分为3层后(0~0.4,0.4~1.0、1.0~3.0m)分析显示,从流动沙丘到1964年固沙区,土壤有机碳密度显著增加(0.18kg·m~(-2)到0.52kg·m~(-2)),且浅层(0~0.4m)的增加快于深层(1.0~3.0m);同时,浅层有机碳密度在整个剖面中所占比例显著增加(14.3%到30.4%),而深层减少(64.8%到51.6%)。浅层和深层无机碳密度均有增加趋势,但差异不显著。冗余分析显示,土壤细颗粒含量、水分有效性、总氮含量、总磷含量、pH值和电导率与土壤碳密度关系密切,解释了土壤碳密度86.2%的变异。土壤有机碳密度与土壤细颗粒、总氮总磷含量及水分有效性、电导率极显著正相关(P<0.001);土壤无机碳密度与土壤细颗粒、总磷含量及水分有效性、总氮含量显著正相关(P<0.05)。在1.0~3.0m和0~3.0m剖面上,土壤有机碳密度与土壤水分含量分别存在显著和极显著的负相关关系(P<0.05和P<0.01)。
Sand fixation plants (1964, 1981, 1990) and moving sand dunes established in different years in the Shapotou area, southeastern margin of the Tengger Desert, were used to sample and analyze the soil from the 0 ~ 3.0 m section to investigate the effects of sand fixation The Influence of Establishment and Development on the Distribution of Soil C (Organic Carbon and Inorganic Carbon) and Its Relationship with Soil Properties. The results showed that the contents of soil organic carbon and inorganic carbon in the surface layer (0 ~ 0.1m) increased obviously after the establishment of artificial sand-fixing vegetation in mobile sand dunes in recent 50 years. The soil organic carbon content was 1.95g · kg -1, Dune 6.67 times, inorganic carbon content of 4.19g · kg ~ (-1), 1.46 times the mobile dunes. After dividing the soil profile into three layers (0 ~ 0.4, 0.4 ~ 1.0, 1.0 ~ 3.0m), the density of soil organic carbon increased significantly (0.18 kg · m -2) from the mobile sand dune to the 1964 sandy desertification area. To 0.52 kg · m -2, and the increase of shallow layer (0-0.4 m) was faster than that of deep layer (1.0-3.0 m). Meanwhile, the proportion of shallow organic carbon in the whole section increased significantly 14.3% to 30.4%), and deep reduction (64.8% to 51.6%). The density of shallow and deep inorganic carbon both increased, but the difference was not significant. Redundancy analysis showed that soil fine particle content, water availability, total nitrogen content, total phosphorus content, pH value and conductivity were closely related to soil carbon density, explaining the variation of 86.2% of soil carbon density. Soil organic carbon density had a significantly positive correlation with soil fine grain, total nitrogen, total phosphorus, water availability and conductivity (P <0.001). Soil inorganic carbon density was positively correlated with soil fine grain, total phosphorus and water availability, Content was significantly correlated (P <0.05). There were significant and highly significant negative correlations between soil organic carbon density and soil moisture content at 1.0-3.0m and 0-3.0m profiles (P <0.05 and P <0.01).