That reclaiming in steep slop land extend the area of dry sloping field plays an most important role in soil and water loss and forest eco-environment serious poor in karst area of Guizhou province.

• 陡坡开垦使旱坡耕地面积扩大是造成贵州省岩溶山区水土流失严重和林业生态建设艰难的根本原因。