Lack of vegetative cover largely caused by such human activities as firewood collection, intensive grazing, and deforestation have accelerated the process of desertification at high elevation watersheds in Nepal. Mountain environment at high elevation is delicate and regeneration of vegetation is slow. Livestock grazing and firewood collection are the basic needs of the people. However, constant human pressure on natural vegetation upsets the hydrologic processes and results in disastrous soil

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... rosion. Desertification caused by long-term soil erosion in semi-arid regions of Mustang district (a severely desertified, high elevation area) in Nepal probably indicates the future of other high elevation watersheds, if corrective measures are not implemented to reduce the rate of degredation of mountain environment. Revegetation of denuded watersheds is not only important to reduce further deterioration of the watersheds but also necessary to produce adequate forage and firewood to meet the demand of years to come. One of the ways of reclaiming desertified land is by revegetation, but vegetation establishment at high elevation is difficult due to various climatic stresses. With little information about vegetation-climate-human interactions at high elevations, revegetation of denuded high elevation watersheds in Mustang has been difficult. In this thesis I review literature on causes of desertification in semi-arid areas; plant responses and functions under different climatic stresses such as water, wind, and salinity; problems associated with vegetation establishment under climatic stress conditions; and reclamation techniques developed by the U.S. scientists in reclaming surface mines of the western United States. Land disturbed by surface mining in the western U.S. has some similarities with desertified land. However, surface mine spoils may pose similar or in some cases greater difficulties in reclamation than desertified areas if there are toxic materials in the mine spoils. There is potential for application of som [...]