西南喀斯特地区土壤水分变异性研究

Study on Variation of Soil Moisture in Karst Regions,Southwest China

中国西南喀斯特地区的石漠化问题严重地制约了当地经济的发展,揭示土壤水分变异性规律对该区域生态系统适应性修复具有重要的意义。笔者以贵州省荔波县和普定县为研究区,通过野外采样和实验室分析,对西南喀斯特地区典型石漠化阶段的土壤水分变异性进行了研究,结果表明:(1)随着石漠化程度的加深,土壤水分含量逐渐减少;(2)土壤水分含量随时间变化明显,在夏季达到峰值,然后呈下降趋势,至冬季达到最低值,随后又逐渐增加,同时随着石漠化程度的加深,其土壤含水量的变化幅度呈减少趋势;(3)未石漠化土壤的蓄水、水分释供能力及土壤有效水含量明显高于石漠化土壤;(4)土壤含水量与容重、孔隙度、颗粒组成及土壤有机质等土壤性质关系密切。通过封山育林等措施提高土壤有机质、水分含量,对于防治喀斯特地区石漠化和进行水土保持具有重要意义。

The Karst regions of southwest China are greatly suffered from rocky desertifieation. The research on the variations of soil moisture is important to the repair of local ecosystem. Soil samples were collected from Libo and Puding in Guizhou province. The variations of soil moisture under typical rocky desertification stage were studied. The results were as follows： （1） as the rocky desertification progressed, the content of soil moisture decreased. （2） The content of soil moisture varied with time significantly. It reached the highest in summer and then kept decreasing until winter. As the rocky desertification progressed, the soil moisture decreased. （3） The storage and releasing capacity as well as the available soil moisture content of non-degraded soil is higher than that of degraded soil obviously. （4） Soil moisture content was related to soil properties such as bulk density, porosity and particle composition and soil organic matter. Forest conservation is an effective way to prevent rocky desertification and soil erosion by enhancing the content of soil organic matter and soil moisture.