纳帕海流域典型植被类型的土壤水分状况及其影响因素

Soil Moisture Regime Under Different Types of Vegetation Typical of Napahai Catchment and Its Influencing Factors

以纳帕海流域荒草地、松树林地、裸地、3 a修复区和1 a修复区5种典型植被类型为研究对象,测定其土壤水分、产流产沙、容重和有机碳含量等,研究不同植被类型土壤含水量差异及其影响因素,对当地脆弱生态水文环境的保护和区域可持续发展的实现具有积极意义。结果表明,不同植被类型土壤含水量φ差异明显,荒草地最高,为50.7%,3 a修复区和松树林地分别为34.5%和28.7%,而裸地和1 a修复区仅有20%左右;不同植被类型土壤理化特性无明显规律性;地表径流系数差异明显,荒草地最低,仅1.21%,而松树林地为5.73%;荒草地和松树林地泥沙产量低于裸地和1 a修复区。除容重外,土壤含水量与其他理化性质和产流产沙相关性均不显著。先种草迅速增加地表覆盖度的植被恢复方式可快速改善表层土壤性质,增强土壤保水能力。

Five plots of land under different types of vegetation typical of the Napahai Catchment, i.e. grassland, pine for-est, bare land, 3-year revegetated land and 1-year revegetated land, were selected, and soil water content, runoff, sedi-ment, bulk density and organic carbon content therein measured for exploration of variation of soil water regime with vege-tation and its influencing factors, which is of positive significance to the realization of protection of the local fragile ecologi-cal hydro-environment and sustainable development of the regional economy simultaneously. Results show that soil watercontent varied sharply with vegetation, and was 50. 7%, the highest, in grassland, 34. 5% in 3-year revegetated land,28. 7% in pine forest, and only 20% or so in bare land and 1-year revegetated land. The five plots of land did not differmuch in soil physico-chemical properties, but did in surface runoff coefficient with grassland being the lowest, 1. 21% on-ly, and pine forest being 5. 73%. Grassland and pine forest was lower than bare land and 1-year revegetated land in sedi-ment yield. Soil water content was not significantly related with any soil physico-chemical properties and sediment yield,except for bulk density. Planting grasses may rapidly expand vegetation coverage of a land, which is an effective approachto rapid amelioration of the surface soil layer in physico-chemical properties, and strengthening the soil in water holdingcapacity.