库区生态公益林改造对林地水土流失的影响研究倡

以福建永安安砂库区生态公益林为研究对象,通过设置径流小区,分别在坡度25°和32°的林地中,设计4种不同间伐强度处理(不间伐、20%、40%、60%间伐强度),研究不同间伐强度及间伐后补植枫香两种改造措施对库区生态公益林林地水土流失的影响.结果表明:40%及60%间伐强度林地的水土流失量大于不间伐处理,中高强度间伐后套种枫香的改造措施同样加大了库区生态公益林地的水土流失,但小于间伐措施的流失量,且水土流失量随着坡度的增加而加大.而在适当的低强度间伐(20%间伐强度)条件下,实施两种改造措施之后的库区生态公益林的水土流失量与不间伐处理之间差异并不明显.因此,选择在低坡度(25°)进行适当的低强度(20%间伐强度)间伐并套种枫香等阔叶树种,可达到在兼顾生态效益的同时,科学合理地利用生态公益林的林木和景观资源的目的

Study on the Effect to the Soil Erosion by the Ecological Public Welfare Forest Rehabilitation in the Reservoir Area

Aiming at the ecological welfare forest in the Ansha Reservoir area of Yong＇ an City, it is designed four dif- ferent thinning intensity treatments （ no thinning, 20%, 40% and 60% thinning intensity） at the forest lands with the slope degree of 25°and 32°respectively through setting the runoff plots to research the impact on the soil loss at ecologi- cal public welfare forest land in the reservoir area by two rehabilitation measures, i.e. the thinning at different intensi- ties and the repair planting of sweet gum after thinning. The results show that soil erosion in the forest land with the thinning intensities of 40% and 60% is higher than that of in the land without thinning treatment, while the inter - planting the sweet gum in the land after the thinning with the middle and high intensities also increase soil erosion in the ecological welfare forestland in the reservoir area. However, the soil erosion caused by the later measure is lower than that of the former with thinning measure, and the soil erosion increases followed the increase of the slope degrees.Under the condition of suitable low intensity thinning （20% thinning intensity）, implementation of two rehabilita- tion measures will not cause the obvious difference of soil erosion compared with the land without thinning treatment. Therefore, it may reach the ecological benefit and the scientific use of trees and scenic resources of the ecological wel- fare forest as well through the combination of the thinning at low intensity （20% thinning intensity） and inter- plant- ing of sweet gum and other broadleaf species.