典型生态系统定位观测样地的土壤性状空间变异性评价

用经典统计分析和地统计学的方法，对中国生态系统研究网络（CERN）临泽站新设置的农田生态系统综合观测场土壤性状的空间分布特性进行研究。结果表明，除pH外，土壤有机碳、全N、速效养分和电导率的变异性均超过20％，有机碳和全N的空间相关距离为13．8m和12．6m，表现出较高的空间异质性。克里格插值结果同样显示土壤各性状在研究的尺度上有明显的空间变异格局。相对误差为10％时采集124个土样才可达到95％的置信水平。作为生态网络长期监测样地，必须按空间异质性对观测场地进行采样分区、匀地过渡，结合克里格插值得出的土壤性状空间分布图，确定更为理想的取样方案。

Assessment of Soil Properties Spatial Variation in Long-Term Observation Field in Study of Ecosystem

It was carried out to examine the characteristic of soil properties and their spatial heterogeneity on the comprehensive observation field of Iinze farmland ecosystem network using methods of classical statistics and geostatistics. The results showed that the variance coefficients of soil organic C, total N, available N, available P, available K, pH and electrical conductivity were more than 20% except pH. The range of soil organic C and total N were 13.8 m and 12.6 m, which indicated the high degree of spatial variability. The kriged soil properties distribution maps showed the same result. Taken 10% as a relative error, collecting 124 soil samples only could reach the significance level of 95 %. As long-term observation field, sampling subarea and field uniformization could be taken on. A more precise sampling scheme could be made based on spatial distribution pattern of test soil properties.