Vegetation Restoration in the Dry and Dry-hot Valley Areas

Dry-hot valleys(DHV) are mainly located in the deeply incised valleys along the upper streams of some national and international rivers, such as the Yangtz River, the Pear River, the Lancangjiang(Mekong) River, and the Red River etc.Because of the unstable geological texture, shallow soil, and a half-year long dry period with little rainfall, the ecological environment in DHV areas is quite vulnerable.Moreover, the ecological environment in these areas has been severely influenced by over farming due to population expansion, and it has become extremely fragile.The primary vegetation in the local area of dry-hot valleys used to be evergreen broad-leaved forests and deciduous broad-leaved forests, which had been denuded in the history.The current local vegetation is mainly the degraded secondary vegetation composed of savanna styled grassland and succulent thorny shrubs.A series of pilot research projects demonstrating new silviculture techniques for vegetation restoration in DHV areas have been implemented.However, it is still hard to carry out large scaled afforestation programs in DHV areas.