CSFD Topic Briefs - February 2011

Coordinator: R. Escadafal, Chair of CSFD Authors: R. Bellefontaine, M. Bernoux, B. Bonnet, A. Cornet, C. Cudennec, P. D’Aquino, I. Droy, S. Jauffret, M. Leroy, M. Malagnoux, M. Réquier-Desjardins, Members of CSFD Editor: S. Jauffret, Ecological Consultant

The African Great Green Wall project What advice can scientists provide? www.csf-desertifi cation.org/great-green-wall

This fact sheet summarizes the key points. and with low total volumes (100–600 mm of Three misconceptions should be clarifi ed rain per year). before being able to shed light on the issue and provide useful advice. Population concentration and the development of often ill-adapted Misconception n°1: agrosilvopastoral activities are the main The desert is a disease factors underlying the desertifi cation process. Renewable natural resources are The Sahara is sometimes considered then overtapped, without leaving suffi cient as a kind of disease that spreads into time for these resources to be regenerated, surrounding areas. However, this desert is while land degradation is exacerbated by actually a healthy and precious ecosystem drought. GGW path with a that, like other deserts worldwide, simulated 15 km contributes to the Earth’s diversity and Misconception n°3: A great width wealth. It is not in any way the image of an forest wall could be planted in (image NASA- MODIS, processing unhealthy environment. Global warming uninhabited or sparsely inhabited Claire Marais-Sicre, CESBIO, 2010) has modifi ed its extension pattern in the regions past, and current climatic changes could lead to a gradual shift in some of the desert On the contrary, the proposed trajectory boundaries. is to pass through inhabited regions The pan-African Great Green Wall where agriculture and livestock farming (GGW) is an initiative that was initially Misconception n°2: The Sahel are already fully developed on lands meant to involve the planting of a is being invaded by a sand sea allocated according to local traditions. 15 km wide transcontinental forest belt Local inhabitants should thus be associated running from Dakar to Djibouti. This Some people think that a gradually with any initiatives designed to combat major project is designed to combat advancing sea of Saharan sand is desertifi cation via . desertifi cation. The band of vegetation relentlessly invading the Sahel, but this is is to be as continuous as possible, not the pattern that scientists have noted. In its current design, GGW is much more but it may be rerouted if necessary to Sand has been shifting in some areas, but than its name or its trajectory suggest—the skirt around obstacles (streams, rocky these are local manageable phenomena note in which its concept is presented (AU, areas, mountains) or to link inhabited and, moreover, the sand does not always CENSAD, Senegal 2008) states that the aim areas (see grandemurailleverte.org). move in a southward direction. Hence, this is to ensure the planting and integrated is not a continent-wide movement trend development of economically interesting Scientists have and are still being queried that should be halted like an invader. drought-tolerant plant species, water by people, NGOs and donors on the merits retention ponds, agricultural production and feasibility of this project. Members The Sahara is thus a stable desert systems and other income-generating of CSFD are drawing up a summary of ecosystem, whereas the Sahel is affected activities, as well as basic social scientifi c fi ndings to help answer these by desertifi cation. Desertifi cation is not infrastructures. questions. The latest version of this review induced by the invasion of sand from the can be downloaded at: desert, instead it is a unique form of land Planting trees in dryland regions to www.csf-desertifi cation.org/ degradation that occurs in these dryland combat desertifi cation is not a new idea. great-green-wall regions, where rain does fall, but irregularly Some of the most famous large-scale

Comité Scientifi que Français de la Désertifi cation (CSFD) Agropolis International Avenue Agropolis The latest version of this review can be downloaded at: F-34394 Montpellier CEDEX 5 Translated by: D. Manley www.csf-desertifi cation.org/great-green-wall Satellite view of a village in Maradi region Assisted natural regeneration. (Google Maps) Maradi region, Niger (S. Jauffret) Recommandations for decisionmakers

The following recommendations are projects include the Algerian Green Dam easy, even for resource-poor farmers, to based on the analysis of agrosilvopastoral project which, as indicated in published carry out. management results: reports and fi ndings, met with some success but also quite a few failures, Beyond these important technical aspects, n Adopt a fl exible approach in resulting in major project changes. The success considerably depends on the social order to make effective use of the Great Green Wall of has not been setting in which these plant propagation best sustainable land management practices designed as a dam but instead it is a and tree planting projects are conducted. , while taking the results of many completed green belt, gigantic integrated management project The delegation of responsibilities, rights and agroforestry projects, and local to combat desertifi cation in an area of on planted trees, access to products know-how, into account over 4000 km long and 1000 km wide. This from these trees, management and local involves a combination of forest and shrub arbitration conditions and their integration o Identify and boost farmers’ , grassy vegetation cover in in prevailing agropastoral systems are awareness on the most effective farming systems. crucial. Projects in which trees were regeneration techniques, that are easy planted without the participation of local to manage (technically and fi nancially) Many local initiatives and inhabitants were almost always limited and and cost-effective and agroforestry experiments have been nonsustainable. When farmers’ rights and carried out in the Sahel. The multiple uses what they could hope to get back from their p Rely on the decentralization of different tree species and the benefi ts labour remain uncertain, technical efforts process by ensuring the participation for the inhabitants of this region are widely to select the best species, to enable them of inhabitants in planting the GGW and acknowledged. However, the results of to develop properly in modern nurseries highlighting the potential benefi ts for them (improved land fertility, yields and many projects have not been formally using advanced planting techniques, could the diversifi cation of income-generating disseminated, despite the fact that access generate some good results, but only in the activities): to this mine of information, including the short term. errors that should hereon be avoided, • promote very simple village structures such as rural markets, etc. should be made accessible so that fi eld An economic analysis has shown that • reinforce management training managers and stakeholders will know what assisted natural regeneration, which for members of village structures, initiatives could or not work. requires little investment, is the most including women cost-effective for resource-poor farmers. • set up a suitable institutional Research is still supported by available However, more intensive collective framework for fi scal and land knowledge and is progressing. Hence, initiatives have a more clearcut impact planning, while ensuring a recent conference in Dakar (2010) when the timeframe is long. decentralization in order to strengthen local resource highlighted the merits of research for management, planning and enhancing the effi ciency of atmospheric Projects will therefore be more successful development control capacities nitrogen fi xation by trees that have when designed for long-term application developed a symbiotic relationship with and within a more global sustainable land q Foster agricultural and livestock bacteria or fungi on their roots, thus management framework. Tree planting, farming intensifi cation, so as to reduce facilitating the colonization of low fertility propagation and regeneration are actually pressure on forest resources. . part and parcel of other agrosilvopastoral All of these recommendations are family farming activities whereby trees are geared towards the integration of There are also many interesting results grown to generate fuel, fodder, resins and tree planting and regeneration in a on vegetative reproduction techniques and gum, building materials and medicinal global sustainable land management assisted natural regeneration, which are products. „ framework.