What Actions Can Be Taken to Prevent Desertification?采取何种措施来防止荒漠化？

The creation of a “culture of prevention” can go a long way towards protecting drylands from the onset of desertification or its continuation. The culture of prevention requires a change in governments’ and peoples’ attitudes through improved incentives. Young people can play a key role in this process. Evidence from a growing body of case studies demonstrates that dryland populations， building on long-term experience and active innovation， can stay ahead of desertification by improving agricultural practices and enhancing pastoral mobility in a sustainable way. For example， in many areas of the Sahel region， land users are achieving higher productivity by capitalizing on improved organization of labor， more extensive soil and water conservation， increased use of mineral fertilizer and manure， and new market opportunities.

Integrated land and water management are key methods of desertification prevention. Sustainable land use can address human activities such as overgrazing， overexploitation of plants， trampling of soils， and unsustainable irrigation practices that exacerbate dryland vulnerability. Management strategies include measures to spread the pressures of human activities， such as transhumance （rotational use） of rangelands and well sites， stocking rates matched to the carrying capacity of ecosystems， and diverse species composition. Improved water management practices can enhance water-related services. These may include use of traditional water-harvesting techniques， water storage， and diverse soil and water conservation measures. Maintaining management practices for water capture during intensive rainfall episodes also helps prevent surface runoff that carries away the thin， fertile， moisture-holding topsoil. Improving groundwater recharge through soil-water conservation， upstream revegetation， and floodwater spreading can provide reserves of water for use during drought periods.

Maintaining vegetative cover to protect soil from wind and water erosion is a key preventive measure against desertification. Properly maintained vegetative cover also prevents loss of ecosystem services during drought episodes. Reduced rainfall may be induced if vegetation cover is lost due to overcultivation， overgrazing， overharvesting of medicinal plants， woodcutting， or mining activities. This is usually coupled with the effect of reduced surface evapotranspiration and shade or increased albedo.

In the dry subhumid and semiarid zones， conditions equally favor pastoral and cropping land use. Rather than competitively excluding each other， a tighter cultural and economic integration between the two livelihoods can prevent desertification. Mixed farming practices in these zones， whereby a single farm household combines livestock rearing and cropping， allows a more efficient recycling of nutrients within the agricultural system. Such interactions can lower livestock pressure on rangelands through fodder cultivation and the provision of stubble to supplement livestock feed during forage scarcity （and immediately after， to allow plant regeneration） due to within- and between-years climatic variability. At the same time， farmland benefits from manure provided by livestock kept on fields at night during the dry season. Many West African farming systems are based on this kind of integration of pastures and farmland.

Use of locally suitable technology is a key way for inhabitants of drylands at risk of desertification to work with ecosystem processes rather than against them. Applying a combination of traditional technology with selective transfer of locally acceptable technology is a major way to prevent desertification. Conversely， there are numerous examples of practices—such as unsustainable irrigation techniques and technologies and rangeland management， as well as growing crops unsuited to the agroclimatic zone—that tend to accelerate， if not initiate， desertification processes. Thus technology transfer requires in-depth evaluation of impacts and active participation of recipient communities.

Local communities can prevent desertification and provide effective dryland resource management but are often limited by their capacity to act. Drawing on cultural history and local knowledge and experience， and reinforced by science， dryland communities are in the best position to devise practices to prevent desertification. However， there are many limitations imposed on the interventions available to communities， such as lack of institutional capacity， access to markets， and financial capital for implementation. Enabling policies that involve local participation and community institutions， improve access to transport and market infrastructures， inform local land managers， and allow land users to innovate are essential to the success of these practices. For example， a key traditional adaptation was transhumance for pastoral communities， which in many dryland locations is no longer possible. Loss of such livelihood options or related local knowledge limits the community’s capacity to respond to ecological changes and heightens the risk of desertification.

Desertification can be avoided by turning to alternative livelihoods that do not depend on traditional land uses， are less demanding on local land and natural resource use， yet provide sustainable income. Such livelihoods include dryland aquaculture for production of fish， crustaceans and industrial compounds produced by microalgae， greenhouse agriculture， and tourism-related activities. They generate relatively high income per land and water unit in some places. Dryland aquaculture under plastic cover， for example， minimizes evaporative losses， and provides the opportunity to use saline or brackish water productively. Alternative livelihoods often even provide their practitioners a competitive edge over those outside the drylands， since they harness dryland features such as solar radiation， winter relative warmth， brackish geothermal water， and sparsely populated pristine areas that are often more abundant than in non-drylands. Implementation of such practices in drylands requires institution building， access to markets， technology transfer， capital investment， and reorientation of farmers and pastoralists.