青海省海北州典型高寒草甸土壤质量评价

Soil quality assessment of alpine meadow in Haibei State of Qinghai Province

以青海省海北州的典型高寒草甸（金露梅灌丛草甸、矮嵩草草甸、高山嵩草草甸）为研究对象,以7种土壤微生物活性指标和10种土壤理化性质指标组成的土壤生物肥力性质为评价指标,对不同利用方式下草甸的土壤质量进行主成分分析（PCA）.结果表明：高寒草甸土壤综合质量可用3个主成分（PC）来表征,其中PC1上有13个指标的载荷较高,PC2上有3个指标的载荷较高,PC3上只有全磷的载荷较高.结合Norm值的方法,筛选出微生物生物量碳、脲酶、碱性磷酸酶、蛋白酶、有机碳、全氮、有效氮、有效磷、有效钾、容重和阳离子交换量（CEC）等11项指标,建立了海北高寒草甸土壤综合质量评价的最小数据集（MDS）.通过主成分和对应的权重系数分析,对3种草甸的土壤综合质量进行排序,0~10 cm层为矮嵩草草甸〉金露梅灌丛〉高山嵩草草甸;10~20 cm层为金露梅灌丛〉高山嵩草草甸〉矮嵩草草甸.

Taking the typical alpine meadows Potentilla froticosa shrub meadow,Kobresia humilis meadow,and K.pygmaea meadow in the Haibei State of Qinghai Province as the research objects,a comprehensive assessment of soil quality was conducted by principal component analysis（PCA）,with seven indices of soil microbial activities and ten indices of soil chemical properties.The soil quality of the alpine meadow could be characterized by three principal components（PC）.In the first component（PC1）,13 indices had high factorial loads;in the second component（PC2）,3 indices had high factorial loads;in the third component（PC3）,only one index,total phosphors,had high factorial load.In combining with Norm values,eleven indices including microbial biomass carbon（MBC）,urease,alkaline phosphatase,protease,organic matter,total N,available N,available P,available K,bulk density,and CEC were selected to establish minimum data set（MDS） for the comprehensive assessment of soil quality of alpine meadow in Haibei. The PCA and corresponding weight coefficient analysis showed that the soil quality（0-10 cm and 10-20 cm layers） of the three kind meadows was in the order of K.humilis meadow P.froticosa shrub meadow K.pygmaea meadow,and P.froticosa shrub meadow K.pygmaea meadow K.humilis meadow,respectively.