青海湖高寒湿地土壤有机碳空间分布分析

Spatial distribution of soil organic carbon under alpine wetland around Qinghai Lake

作为陆地碳库的主要部分,土壤有机碳在全球碳循环中起着重要作用.本文选取环青海湖高寒湿地土壤为研究对象,对土壤有机碳含量的变化特征及其空间变异性进行了研究.结果显示,环青海湖区土壤有机碳0-10cm表层含量最高,均值为2.82±1.56%,随着土层深度的加深其含量逐渐降低.10-20cm、20-30cm和30-40cm土层的有机碳平均含量依次为2.01±1.03%、1.63±0.87%和1.21±0.91%;整个研究区0-40cm土壤有机碳平均含量仅为1.92±1.27%.半方差函数和变异函数分析结果说明,0-10cm,10-20cm和20-30cm土层土壤有机碳含量的模型均符合球状模型,30-40cm土层土壤有机碳含量和0-40cm土壤有机碳平均含量的模型为指数模型.而且在各向同性和各向异性下不同深度土壤有机碳均具有高度的空间异质性.

As a major part of terrestrial carbon pools, soil organic carbon plays an important role in the global carbon cycle. Selected alpine wetland soil in Qinghai Lake for study object, this paper studied characteristics of soil organic earbon（SOC）content and its spatial variability. Results showed that soil organic carbon content in the 0-10 cm soil layer was the highest,with mean of 2. 82±1.56%. With the depth of the soil deepening, its content was decreased gradually, the average content of soil organic carbon in the 10-20 cm,20-30 cm and 30-40 cm soil layer was 2.01±1.03%, 1.63＋0.87% and 1.21±0.91%, respectively; the average content of soil organic carbon in the 0-40 cm layers throughout the study area was only 1.92 ± 1.27-. Semi-variance function and the variogram analysis results showed that the models of soil organic carbon content in the 0-10 cm, 10-20 cm and 20-30 em soil layers obeyed the spherical model, The models of SOC in 30-40 cm layer and the average of 0-40 cm layer obeyed the exponential models. And also the analyses of the soil organic carbon isotropic and anisotropicunder different depths indicated that SOC existed in higher spatial heterogeneity.