【摘要】 以重庆中梁山岩溶山地的林地、菜地、草地和弃耕地为研究对象,采用有机碳密度分组法、单因素方差分析和相关分析,研究不同土地利用方式对土壤轻组有机碳(LFOC)和重组有机碳(HFOC)含量、分配及敏感性的影响。结果表明,林地、菜地和草地土壤LFOC、HFOC、有机碳(SOC)含量及LFOC/SOC均显著高于弃耕地;而土壤HFOC/SOC以弃耕地最大。不同土地利用方式下,土壤LFOC、HFOC、SOC含量均随土层深度增加而下降。土壤LFOC敏感性最高,其次为SOC,HFOC敏感性最低。LFOC能更敏感地反映土地利用方式的变化,可作为反映土壤质量变化和土壤有机碳稳定性的敏感性指标。更多还原

【Abstract】 In the present study,forest land,vegetable land,grass land and abandoned land in Karst mountainous area of Zhongliang in Chongqing were selected as study objects. Influences of different land use types on soil light fraction organic carbon( LFOC) and heavy fraction organic carbon( HFOC) contents,distributions and sensitivity were studied using the method of relative density fractionation,variance analysis and correlation analysis. It was shown that contents of soil organic carbon( SOC),LFOC,HFOC and LFOC/SOC in forest land,vegetable land,grass land were significantly higher than those in abandoned land. However,HFOC/SOC in abandoned land were higher than those in the other land use types. The contents of LFOC,HFOC and SOC under different land use types decreased with the increasing soil depth. Soil LFOC had the highest sensitivity,and was followed by SOC and HFOC. Soil LFOC was more sensitive to the land use changes. Therefore,soil LFOC could be used as indicator of soil quality and soil organic stability.更多还原