金沙江上游滇西北高原水土保持生态修复效果

Effect of eco-restoration for soil and water conservation in northwest plateau of Yunnan province in upper reaches of Jinsha river

通过对金沙江上游滇西北高原植物群落调查、土壤理化分析、径流小区观测,对陆生生态系统的退化模式和生态修复效果进行研究。结果表明:人为干扰形成的退化生态系统通过人为诱导修复,可在较短时间内形成功能较完善的人工生态系统。灌丛、次生林、人工混交林都已经形成明显的立体垂直结构,并有正向演替趋势。荒草丛、灌丛、人工混交林和次生林的Shannon-Wiener多样性指数分别为2．29、2．58、2．04和2．03,对应的Pielou均匀度指数分别为0．80、0．81、0．67和0．65。灌丛的土壤理化效应最佳,其0～30 cm土层土壤总孔隙度分别比坡耕地、荒草丛、天然次生林、人工混交林高8．7％、24．7％、45．9％和14．3％,有机质含量分别高19．3％、15．9％、276．8％和 50．9％。天然次生林由于本底立地条件差,理化性能赶不上其他类型。人工幼林和天然次生林有较好的减轻土壤流失的作用,分别比坡耕地减少土壤侵蚀量38．0％和52．3％,比荒草坡减少土壤侵蚀量25．0％和42．3％。

To investigate the effect of effect of eco-restoration for soil and water conservation in the northwest plateau of Yunnan province in upper reaches of Jinsha river, based on surveying vegetation community struc- ture, analyzing soil chemical and physical properties, and observing runoff and soil loss in plots, effects of eco-restoration are researched. Results show that degraded eco-systems formed by manmade interference can be formed in a manmade ecosystem of perfect function in short time by manmade induction. The obviously vertical structure and positively successive ecosystem already formed in the ecosystem types of shrub, natural secondary forest and artificial mixed forest. The Shannon-Wiener variety indexes of wild grass, shrub, artificial mixed forest and natural secondary forest respectively are 2.29, 2.58, 2.04 and 2.03, and the Pielou homogeneity index JH respectively are 0.80, 0.81, 0.67 and 0.65. The shrub type is the best eco-system on soil chemical and physical property, whose total soil porosity in 0-30 cm soil layer is 8.7%, 24.7%, 45.9% and 14.3% respectively higher than that of slope farmland, wild grass, natural secondary forest and artificial mixed forest, while the soil organic content is 19.3%, 15.9%, 276.8% and 50.9% higher respectively. The soil property of the natural secondary forest is the worst because of the bad natural environmental conditions. The artificial young forest and natural secondary forest can protect the soil from erosion very well, whose soil erosion amount respectively are 38.0 % and 52.3 % less than that of slope land and 25.0 % and 42.3 % less than that of wild grass land.