Desertificación

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6. How can we prevent or reverse desertification?

• 6.1 Why are actions needed?
• 6.2 What actions can be taken to prevent desertification?
• 6.3 What actions can reverse land degradation?

The source document for this study states:

"Effective prevention of desertification requires both local management and macro policy approaches that promote sustainability of ecosystem services. It is advisable to focus on prevention, because attempts to rehabilitate desertified areas are costly and tend to deliver limited results."

Source & ©: MA Desertification Synthesis Report (2005),
Chapter 5, p.14

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6.1 Why are actions needed?

The source document for this study states:

"Rationale

Major policy interventions and management approaches are needed to prevent and reverse desertification. Assessment of future scenarios shows that major interventions and shifts in ecosystem management will be needed to overcome challenges related to desertification. As recognized by the UNCCD, such interventions are to be implemented at local to global scales, with the active engagement of stakeholders and local communities. Improved information generation and access, as noted in the final section, will help create enabling conditions for this implementation (S14 .4.2, C6 .6).

Societal and policy responses vary according to the degree of desertification that a society faces.This intensity of responses needs to be reflected accordingly in National Action Programmes stipulated by the UNCCD and their subsequent implementation. In areas where desertification processes are at the early stages or are relatively minor, it is possible to arrest the process and restore key services in the degraded areas. The adverse impacts of desertification on dryland ecosystem services and limited success in rehabilitation demonstrate that it is more cost-effective to
prevent desertification (C22 .3.2, C22 .6, R17 ).

Addressing desertification is critical and essential to meeting the Millennium Development Goals.The human well-being of dryland people, about 90% of whom are in developing countries, lags significantly behind other areas. Approximately half of the people worldwide who live below the poverty line live in drylands. The combination of high variability in ecosystem conditions in drylands and high levels of poverty leads to a situation where societies are vulnerable to a further decline in human well-being. Addressing desertification therefore facilitates eradication of extreme poverty and hunger, as envisioned in the MDGs. This also complements directly the policies to be included in NAPs to combat desertification (C22 .ES)."

Source & ©: MA Desertification Synthesis Report (2005),
Chapter 5, p.14

Next Sub-Question

6.2 What actions can be taken to prevent desertification?

The source document for this study states:

"Prevention

Truck with wood
Source: MA

The creation of a “culture of prevention” can go a long way toward 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 (C22 .3.1).

Integrated land and water management are key methods of desertification prevention. All measures that protect soils from erosion, salinization, and other forms of soil degradation effectively prevent desertification. 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 (C22 .2.3, C22 .4.3, C22 .4.4, R6 .2.2, R6 .3.7).

Protection of vegetative cover can be a major instrument for prevention of desertification. 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 (C22 .2.3, C22 .2.2, C13  Box 13.1).

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 (C22 .2.6, R6 .3.7).

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 (R.SDM, R17 .2.4, R14 .ES).

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 (C22 .ES, C22 .6.4, R6 .2.2, R17 .3, R2 .4.3).

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 (C22 .4.4).

Desertification can also be avoided by creating economic opportunities in drylands urban centers and areas outside drylands. Changes in overall economic and institutional settings that create new opportunities for people to earn a living could help relieve current pressures underlying the desertification processes. Urban growth, when undertaken with adequate planning and provision of services, infrastructure, and facilities, can be a major factor in relieving pressures that cause desertification in drylands. This view is relevant when considering the projected growth of the urban fraction in drylands, which will increase to around 52% by 2010 and to 60% by 2030 (C22 .5.2, C27 .2.3)."

Source & ©: MA Desertification Synthesis Report (2005),
Chapter 5, p.14-15

Next Question

6.3 What actions can reverse land degradation?

The source document for this study states:

"Reversal of Land Degradation

Terracing prevents further gully erosion and stores surface runoff for olive production (Tunisia)
Source: MA

The goal of rehabilitation and restoration approaches is to restore ecosystem services that have been lost due to desertification.This is achieved through a positive change in the interaction between people and ecosystems. Restoration is an alteration of a degraded site to reestablish a defined native ecosystem state and all its functions and services. Rehabilitation seeks to repair damaged or blocked parts or sectors of ecosystem functions, with the primary goal of regaining ecosystem productivity. Like the benefits of increased education or improved governance, the protection, restoration, and enhancement of ecosystem services tend to have multiple benefits (C2.2.3, CF.SDM).

Effective restoration and rehabilitation of desertified drylands require a combination of policies and technologies and the close involvement of local communities.Examples of measures to restore and rehabilitate include establishment of seed banks, restocking of soil organic matter and organisms that promote higher plant establishment and growth, and reintroduction of selected species. Other rehabilitation practices include investing in land through practices such as terracing and other counter-erosion measures, control of invasive species, chemical and organic nutrient replenishment, and reforestation. Policies that create incentives for rehabilitation include capacity building, capital investment, and supportive institutions. Community involvement in conceptualization, design, and implementation is essential for rehabilitation approaches. For example, many of the policies for combating desertification tried in the Sahel during the 1970s and 1980s failed because they did not involve local land managers (C22 .3.2, R2 .4.3).

For desertified areas, rehabilitation strategies have a mix of positive and negative impacts on ecosystems, human well-being, and poverty reduction. The success of rehabilitation practices depends on the availability of human resources, capital for operation and maintenance, infrastructure development, the degree of dependence on external sources of technology, and cultural perceptions. Adequate access to these resources, combined with due consideration of the needs of local communities, can lead to successful rehabilitation of some ecosystem services and hence reduce poverty. Some success stories have been observed; for example, farmers in the Machakos (Kenya) restored degraded lands. This was achieved through access to markets, off-farm income, and technologies that increased land and labor productivity faster than population growth.

In cases where these conditions are not met, efforts to rehabilitate fail. For example, in response to the 1930s Dust Bowl in the United States, major policy interventions were introduced, including zoning laws for the most fragile areas, repurchases of submarginal private land, cash payments for leaving land fallow, and farm loans tied to approved land practices. These economic reforms, coupled with the migration of 1 million people in 1940–70, could not prevent the return of the problem as Dust Bowl II in the 1950s and Dust Bowl III in the 1970s. This demonstrates that restoring degraded dryland services may be difficult even with major policy and technological interventions (C5 .ES, C5  Box 5.1, C22 .3.2)."

Source & ©: MA Desertification Synthesis Report (2005),
Chapter 5, p.16