毛乌素沙地地表土团聚体赋存状况

研究土壤团聚体的赋存状况对于土地利用与恢复以及防控土壤风蚀沙化具有重要意义。在野外采样的基础上,通过实验测试和相关统计分析对毛乌素沙地不同生境下表土土壤团聚体的性状及其与土壤有机质的相关性进行了研究。结果表明,该区土壤团聚体组成总体上以0.25~0.50mm的微团聚体为主;不同土层深度土壤团聚体含量存在差异,表土团聚体含量表现为0cm10cm20cm;不同生境条件下土壤团聚体含量也存在差异,其中杨树(Populus)林地和拂子茅(Calamagrostise pigeios)草地表层土(0cm)中1mm粒径的土壤干筛团聚体含量较高,分别达到4.27%和3.55%;总体而言,由于毛乌素沙地环境条件中水分的短缺,土壤团聚体发育缓慢且稳定性较差;土壤团聚体在有植被保护或恢复较好区域正在逐渐优化。有机质是影响团聚体赋存和稳定性的重要因素。

A study of the aggregate structure of topsoil in Mu Us Sandland in China

The study and analyses of the structure of the topsoil aggregates is important to make informed decisions not only for the ecological restoration of the land,but also to prevent erosion of the topsoil.The aim of this study was to analyse the properties of the aggregates and their interdependencies at different depths of topsoil taken from the Mo Us region.The results illustrate that the diameter of the aggregates in the region measure between 0.25～0.50 mm.The contents of the aggregates differed with the depth and with biotope conditions.The maximum content of aggregates of size greater than 1 mm was seen in land covered with willow and Calamagrostis pigeios land constituted 4.27％ and 3.55％,respectively.The analysis of the aggregate stability indicated that the soil in this region is not fully developed and is unstable.The soil structure appears to be gradually developing in the areas protected by vegetative cover or those that arerestoration areas,implying that organic matter is the most important factor influencing the occurrence and stability of aggregates in topsoil.