开垦对草甸土有机碳的影响  

Effects of Reclamation on Soil Organic Carbon of some Meadow Soils

作　　者：陈伏生[1] 曾德慧[1] 陈广生[1] 范志平[1] 

机构地区：[1]中国科学院沈阳应用生态研究所

出　　处：《土壤通报》2004年第4期413-419,共7页Chinese Journal of Soil Science

基　　金：国家科技攻关计划项目(2002BA517A11-5);中国科学院知识创新工程重要方向(KZCX3-SW-418);内蒙古自治区"十五"科技攻关课题(20010103)资助

摘　　要：本文利用经典统计学和地统计学相结合的方法,选取科尔沁沙地东南缘草甸土两块10×10m的样地为例,分析了草地开垦8a后的耕地耕作层土壤有机碳含量和空间分布格局的变化,结果表明:草地与耕地表层(0～10cm)土壤有机碳含量差异不显著,草地亚表层(10～20cm)土壤有机碳含量低于耕地(p<0.05);草地与耕地表层和亚表层土壤有机碳空间分布格局具有明显差异,表现为草地的表层和亚表层的结构异质性分别大于耕地,分数维小于耕地,空间依赖性强于耕地,空间分布格局的破碎程度弱于耕地。耕地表层与亚表层土壤有机碳含量差异不显著(p<0.05),但空间结构特征和空间分布格局存在明显的差异;而草地表层与亚表层土壤有机碳含量差异显著(p<0.05),但空间结构特征和空间分布格局比较相似。因此,开垦不仅影响草甸土有机碳含量的高低,而且影响其空间结构特征和分布格局。这对进一步了解草地开垦对土壤有机碳及全球碳循环和气候变化的影响具有重要意义。Two 10×10m plots were set, one in a meadow grassland,and the other in an arable land of meadow, where was reclaimed 8 years ago. The content and spatial pattern of soil organic carbon (SOC) of the cultivation layer of the meadow soils in the southeastern Keerqin Sandy Land was studied by traditional statistics and geostatistics. The results showed that SOC content of 0-10cm layer on the arable land, was similar to that of the virgin grassland, while SOC content of 10-20cm layer was higher than that of the grassland (p<0.05). The spatial pattern of soil organic carbon of the arable land was significantly different from the grassland. The results also showed that the structural heterogeneities and spatial dependence of each layer (0-10cm and 10-20cm) in the arable land were smaller than those in the grassland, the fractal dimension of each layer of the arable land was larger than that of the grassland, and the spatial distribution pattern of the 0-10cm of the arable land was obviously fragmented. The SOM content of the 0-10cm layer remarkably different from the 10-20cm layer on the grassland (p<0.05), however, the spatial structural characters and spatial distribution pattern of the two layers were relatively uniform, while the SOM content and spatial distribution pattern of the arable land had the inverse tendency with that of the grassland (p<0.05). In conclusion, reclamation could not only influence the SOM quantities of the cultivation layer of the meadow soil,but also the SOM spatial structural characteristics and spatial distribution pattern.

关 键 词：土地利用变化 土壤有机碳 地统计学 草甸土 

分 类 号：S153.621[农业科学—土壤学]