喀斯特地区不同林草植被的减流减沙作用

为了进行水土保持生物措施的合理配置,因地制宜治理贵州喀斯特地区水土流失,通过径流小区观测法,对贵州喀斯特地区不同林草植被的减流减沙作用进行了研究.结果显示,观测试验期间(2008-2010年),大部分林草植被类型都经历了明显的变化过程:完全不具减流减沙作用-部分具有减流减沙作用-减流减沙作用.至2010年各林草植被的减流作用的大小顺序为:经济林(减流率为52.5％～64.3％)＞杨树与墨西哥柏混交林＞黑麦草＞墨西哥柏＞白三叶＞杨树；减沙作用的大小顺序为:经济林(平均减沙率达99.3％)＞黑麦草＞杨树与墨西哥柏混交林＞墨西哥柏＞杨树＞白三叶.林草植被配置方式对产流产沙量也有很大影响,因此采取林草措施应同时考虑林草类型和配置方式,才能达到最佳的水土保持效果.

Runoff and Sediment Reduction Effects Under Different Forest and Grass Vegetation in a Karst Area

In order to allocate biological measures for soil and water conservation reasonably,and to controlthe soil and water loss according to local conditions,this study focuses on the analysis of runoff and sedimentreduction effects under different types of forest and grass vegetation by a runoff plot experiment in a karstarea of Guizhou Province.Results show that most types of forest and grass vegetation in the study area hadexperienced three stages during the investigation time period(2008-2010):no effect,partial effect and remarkable effect on runoff and sediment reductions.By the end of 2010,the runoff reduction effect of different types of forest and grass vegetation was economic forests(their runoff reduction rates between 52.5% and64.3%)>mixed forest of poplar and portuguese cypress>ryegrass>portuguese cypress>white clover>poplar forest.The sediment reduction effect of different types of forest and grass vegetation was economicforests(their mean sediment reduction rate was 99.3%)>ryegrass>mixed forests of poplar and portuguesecypress>portuguese cypress forest>poplar forest>white clover.Allocation of forest and grass vegetationalso shows a great difference in runoff and sediment productions,therefore,type and allocation of forest andgrass vegetation should be considered simultaneously to achieve the best soil and water conservation effect.