基于CT的青海湖流域芨芨草草地土壤大孔隙特征分析

为探究青海湖流域芨芨草草地的土壤大孔隙特征,以青海湖流域芨芨草草地为研究对象,在研究区芨芨草斑块处和芨芨草斑块间分别采集原状土柱,每块样地选取3个重复样品,通过对样品进行CT扫描并利用Fiji软件解译的方法分析土壤孔隙的结构特征差异。结果表明:芨芨草斑块土壤平均大孔隙数量、不同深度大孔隙数量、平均大孔隙度以及不同深度大孔隙度均大于芨芨草斑块间土壤。芨芨草斑块土壤大孔隙平均数量是芨芨草斑块之间的2.8倍,平均大孔隙度是芨芨草斑块间的12.1倍,芨芨草斑块的土壤大孔隙度随土壤深度增加呈先增加后减少的趋势,斑块间的大孔隙度呈递减趋势。

Soil Macropore Characteristics of Achnatherum Splendens Steppe in the Qinghai Lake Watershed

Soil macropore characteristics ofAchnatherum splendens Steppe in the Qinghai Lake Watershed of northeastern Qinghai-Tibet Plateau by using computed tomography (CT) was quantified. A plot within aAchnatherum splendens patch and a plot outside aAchnatherum splendens patch were selected, and 3 soil cores (0 – 50 cm deep) were taken as replicates from each plot and scanned with a GE HISPEED FX/I medical scanner. The results indicated that the number of macropores and the macroporosity of soil within theAchnatherum splendens patch were larger than those of soil outside the patch, the mean numbers of macropore and macroporosity of soil within theAchnatherum splendens patch were 2.8 times and 12.1 times greater than those in soil outside the patch. With the increase of soil depth, the macroporosity increased first and then decreased within the Achnatherum splendens patch, while it decreased continuously in soil outside the patch.