乌兰布和沙漠草方格-灌木林对土壤水分物理性质的影响

Effects of typical ecological projects of desertification combating on soil physical properties in Ulan Buh Desert

为探讨乌兰布和沙漠典型防沙治沙生态工程实施后对土壤水分物理性质及持水性能的影响,以流沙地为对照、选择草方格沙障+两种乡土树种(梭梭、花棒)为主的防沙治沙工程为研究对象,采用野外取样与室内分析相结合的方法,对各样地0~100 cm深度内不同土层的土壤粒度组成、水分含量、容重、孔隙度、持水性能等进行了分析。结果表明:营建以草方格沙障+乡土树种为主的防沙治沙生态工程对沙地土壤水分物理性质及持水性能均有一定的改良作用。(1)表层土壤粒度组成整体出现细化趋势,土壤容重减小,土壤孔隙度增大,土壤持水量和贮水量增大,土壤持水性能明显提升。(2)乌兰布和沙漠典型防沙治沙生态工程实施后,土壤成土作用较明显、持水性能明显提升,沙化土地治理效果良好。研究结果可为区域防沙治沙的成效评估提供基础数据,同时也可为区域防沙治沙生态工程的类型选择提供科学依据和参考。

To probe into the effects of typical ecological projects on improving soil moisture and other physical properties like water retention in Ulan Buh Desert,the desertification combating projects included straw checkerboard barrier and two native tree species(Haloxylon ammodendron and Hedysarum scoparium),and the shifting sandy land as the research object.The soil mechanical composition,moisture content,bulk density,porosity,water holding capacity,and water storage capacity of different soil layers at a depth of 0-100 cm were analyzed based on field sampling and lab analysis methods.The results showed that the ecological projects have a certain effect on the improvement of soil water physical properties and water retention of the aeolian sandy soil.(1)Compared to the control,the implementation of ecological projects promoted the apparent refinement of the grain size composition of the surface soil,showing decreased bulk density,increased soil porosity,and significantly increased soil water holding capacity and water storage capacity.(2)After the implementation of the typical ecological projects,the soil water retention was significantly improved,and the desertification land management effect was good.The results can provide basic data for the effective evaluation of regional desertification combating,and provide a scientific basis and theoretical reference for the type of selection of regional desertification combating ecological projects.