摘要:为了阐明土地利用方式对土壤养分含量及土壤碳氮磷生态化学计量特征的影响，选择阴山北麓农牧交错带4种主要的土地利用类型（放牧草地、封育草地、弃耕地和耕地）为研究对象，分析了浅层土壤（0-25 cm）有机碳（SOC）、全氮（TN）、全磷（TP）、碱解氮（AN）和速效磷（AP）含量及土壤C、N、P生态化学计量特征。结果表明：1）研究区土壤贫瘠，养分含量整体水平不高，SOC、TN、TP含量分别为14.57、0.63、0.76 g/kg，AN和AP含量分别为39.87、6.72 mg/kg，5项养分指标均为中等变异。2）土地利用方式对土壤养分含量和土壤C、N、P生态化学计量特征均存在显著的影响，草地（封育草地、放牧草地）的SOC、TN和AN含量均高于农耕地（弃耕地、耕地），而TP和AP含量低于农耕地；草地的C：N、C：P和C：P值均高于农耕地。3）土壤C、N、P元素化学计量值与C、N、P元素之间的最优拟合关系显示C：N、C：P主要受SOC影响，C：P主要受N影响，表明SOC和N含量决定了研究区土壤中C、N、P化学计量特征的变化过程。研究结果对丰富土壤生态化学计量学科学理论具有重要意义，同时可为阴山北麓农牧交错带脆弱生态区的生态功能恢复提供科学依据。



Abstract:The way of land use affects soil nutrients and influences of stoichiometry characteristics was investigated by analyzing four different types of shallow soil (0-25 cm) taken from four different land (grazed grassland, enclosure grassland, abandoned land, farmland) in the northern piedmont of Yinshan Mountain, and the soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), and stoichiometry characteristics were determined. The results were as follows: (1) In general the soil was impoverished and the nutrient content was low in the study area. The soil SOC, TN, and TP were 14.57, 0.63, and 0.76 g/kg, respectively, and the AN and AP were 39.87 and 6.72 mg/kg, respectively. These five indicators showed modest variations. (2) Soil nutrient content and stoichiometry characteristics were significantly affected by land use patterns. The SOC, TN, and AN in grassland (grazed grassland and enclosure grassland) were higher than those in agricultural land (abandoned land and farmland), whereas the TP and AP were lower than those in agricultural land. The C ∶ N, C ∶ P, and C ∶ P ratios in grassland were higher than in agricultural land. Furthermore, the optimal fitting relationship showed that the C ∶ N and C ∶ P ratios were mainly affected by SOC, whereas the C ∶ P ratio was mainly affected by N, which indicated that both factors affected the C, N, and P stoichiometry characteristics in the study area soils. These results have important implications for the theoretical improvement of soil ecological stoichiometry and provide a scientific basis for constructing an ecologically functional recovery program for the fragile ecological zone located in the agriculture-pasture ecotone of northern China.





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