红壤坡地不同树种林下水土流失特征研究

利用浙江省兰溪水土保持综合试验站不同树种的7个径流小区连续9 a(1985-1997年)的监测资料,分析了不同树种林下水土流失的动态过程.结果表明:(1)在树木栽培的前2 a内水土流失较为严重,前2 a内水土流失除茶园地和松树林地外,占9 a水土流失总量的90％以上.随着树龄的增长,林木水土保持功能增加,小区水土流失趋于减缓,部分树种林下的侵蚀产沙接近于零.(2)前2 a内各林地小区水土流失强度排序为:杉树林＞密柑林＞稀柑林＞毛竹林＞混交林.林灌混交林地小区的水土保持功能最为明显.(3)茶园地在生产管理中,由于施肥和采茶等人为的干扰,水土流失没有表现出随树龄的增加而减缓的趋势,其水土流失年际间波动明显.研究表明,在培育水土保持林时,最初2 a内是加强林下水土保持的重要时段,茶园地加强施肥采茶等生产过程的人为干扰更是减少水土流失的关键.

Characteristics of Soil and Water Loss on Red Soil Slope Land Under Forest with Different Tree Species

This paper,aiming at detecting the difference of soil losses under different vegetation types,analyzed the dynamic processes of soil and water loss under forest with different tree species using 9years'dataof 6runoff plots observated in 1995-1997from Lanxi comprehensive test station of soil and water conservation in Zhejiang Province.The results were as following:(1)In the first 2years after tree planting,soil andwater loss were very serious.Soil and water loss were above 90percent of all 9years'except tea garden andpine tree,but the soil loss decreased with tree growth due to improvement of soil and water conservation capabilities of these forest.Soil erosion and sediment yield were almost not detected in some forests;(2)Soilerosion intensity in the first 2years follows an order:china fir forest>dense citrus forest>sparse citrus forest>bamboo forest>mixed forest.The coniferous and broad-leaved mixed forest is the most effective in reducing the soil and water loss;(3)Soil and water loss did not vary with the time,and the significant interannual fluctuations was detected in tea orchard due to the interference of artificial fertilization and pickingtea.Some conclusions could be drawn that in the cultivation processes of soil and water conservation forest,the first 2years was an important period to the control of soil and water conservation.Strengthen the production management of tea garden fertilization and picking tea were specially the key measures to reducingsoil and water losses.