喀斯特地区水土流失动态特征及生态效益评价——以贵州清镇退耕还林(草)示范区为例

A STUDY ON THE DYNAMIC CHARACTERISTICS OF SOIL EROSION AND ECO-BENEFIT EVALUATION IN KARST REGION ——A Case Study on Qingzhen Demonstrating Site of Returning Farmland to Wood( Grass) , Guizhou

喀斯特地区水土流失是生态环境退化的一个重要因素,严重制约着该地区农业可持续发展,如何利用喀斯特地区的坡地资源(如植物资源)是控制水土流失,改善其生态环境的关键。通过对清镇示范区退耕还林(草)和封山育林区的水土流失监测表明,利用恢复植被来控制水土流失,使示范区的土壤侵蚀模数从2000年以前的2500～5000t/km2·a减少至2002年的78.4～185.7t/km2·a;使32.16km2面积的退耕还林(草)和封山育林地段每年减少表土损失量38563.6t,相当于每年减少886.96t化肥的土壤养分流失,其生态、经济、社会效益十分明显。

Soil erosion, an important factor to ecological degradation, seriously controlled the sustainable development of agriculture in karst region. How to make use of the resources in slope land(such as the plant resources)is the key to control soil erosion and improve ecoenvironment. The soil erosion monitoring results in Qingzhen demonstrating site proves that the soil erosion mold number reduced from 2500~5000 t/ km2·a in 2000 to 78.4~185.7 t/ km2·a in 2002 through reforestation, which makes 32.16 km2 land reduced 38563.6 t of topsoil lose, equals to reducing 886.96 t of chemical fertilizer lose every year. So, the ecologic, economic and social benefits is very obvious.