黄河源区高寒草地沙化进程中土壤物理性质的变化(简报)——以玛曲为例

以玛曲县高寒草地为研究对象,采用空间序列代替时间序列的研究方法,对该区不同沙化程度草地的土壤物理性质变化进行分析研究。结果表明,在高寒草地沙化进程中,存在着土壤机械组成不断变粗、土壤容重不同程度增加而孔隙度相应减小的变化趋势。在0~20cm层,植被盖度<50%的中度沙化草地和植被盖度<10%的极重度沙化草地与植被盖度>80%的天然草地相比,土壤中砂粒含量分别提高10.7%和15.2%,土壤容重分别增加9.3%和12.4%,土壤孔隙度分别减小10.4%和13.9%;随沙化程度的加剧,对土壤物理性质的影响层次也有所加深。

A study on the changes of soil physical properties in the desertification process of source regions of the Yellow River using Maqu as an example

The changes in physical properties of soils at different degrees of desertification were studied in the first meander of the Yellow River at the alpine meadow of Maqu County with the substitution of spatial sere for time sere.The results showed that: in the desertification process of the alpine meadow,the soil mechanical constitution tended to gradually become rougher,the weight per unit volume increased to some extent while soil porosity decreased accordingly.Compared with natural grassland where vegetation cover was more than 80%,at 0-20 cm depth the soil sand particle content increased by 10.7% and 15.2%,soil weight per unit volume increased by 9.3% and 12.4%,and bulk density decreased by 10.4% and 13.9% in grasslands with moderate and severe degrees of desertification respectively and whose vegetation covers were less than 50% and 10% respectively.Thus the soil physical properties deteriorated in the desertification process of this alpine meadow,and the soil physical properties in the deeper layers would also be affected as desertification intensified.