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Vicente-Serrano S.M.,CSIC - Pyrenean Institute of Ecology | Begueria S.,CSIC - Aula Dei Experimental Station | Gimeno L.,University of Vigo | Eklundh L.,Lund University | And 9 more authors.
Applied Geography | Year: 2012

Understanding, monitoring and mitigating drought is a very difficult task as a consequence of the intrinsic nature of the phenomenon. In addition, assessing the impact of drought on ecosystems and societies is also a complex task, because the same drought severity may have different consequences in different regions and systems due to the underlying vulnerabilities. New technologies based on geospatial information are available to determine the risk and vulnerability of a system to a drought and to develop monitoring and early warning systems based on real-time information to support decision making. To improve drought preparedness and mitigation, geospatial datasets based on climate information, Earth Observation Systems and statistical and dynamical modelling methodologies can make a noticeably difference in mitigating drought impacts in Africa. In this article we illustrate how the development of drought information systems based on geospatial technology, that combines static and real-time information, could improve the possibilities of drought mitigation in Africa. We stress that it is necessary to go beyond past attempts to manage drought risk based on a reactive crisis-response approach, by promoting drought mitigation and preparedness at the national and regional levels. For this purpose the development of drought information tools is fundamental for the implementation of drought management plans and to support real-time decision-making. © 2012 Elsevier Ltd.

Bayala J.,World Agroforestry Center | Sanou J.,Institute Of Lenvironnement Et Of Recherches Agricoles | Teklehaimanot Z.,Bangor University | Ouedraogo S.J.,Institute du Sahel INSAH | And 3 more authors.
Agriculture, Ecosystems and Environment | Year: 2015

The 'parklands' that form the most widespread farming systems in the Sahelian zone of West Africa are farming systems in which annual crops are grown under scattered trees preserved from the natural vegetation by farmers following clearing the woodlands to make crop fields. Being mixed agricultural systems, the interactions between trees and crops have always been a key element determining the management options applied by farmers. This has also attracted the attention of scientists, with the first studies of this nature dating back to the 1960's. A combination of field trials, observational studies and modeling has been deployed to understand soil-tree-crop interactions, including sharing of growth resources by the system components. Based on this understanding, management options have been discussed with farmers. The most common experimental designs used are transects from the base of tree trunk toward the open field, concentric zones around trees or sectors under trees where various experimental treatments are applied, depending on the objectives of the studies. Key findings disentangled the contributions of each component of the system to the island of high fertility around trees using isotopic techniques, tree effects on adjacent C4 cultivated plants and alternative C3 crops that tolerate tree shade. Tree management practices such as pruning have been tested to modify the crown architecture and the patterns of root distribution in order to improve light availability and resource use efficiency. Increases in land use intensity require more active management by farmers of tree regeneration. Despite scientific advances, there are still some methodological challenges in determining the "park effect", the tradeoffs and synergies between and among goods and services, and how to boost the provisioning, supporting and regulating functions of such agroforestry systems. Providing such ecosystem service functions is critical in the quest for ensuring food security while achieving adaptation and mitigation goals in vulnerable environments like the drylands. © 2015 Elsevier B.V.

Bayala J.,World Agroforestry Center | Sanou J.,Institute Of Lenvironnement Et Of Recherches Agricoles | Teklehaimanot Z.,Bangor University | Kalinganire A.,World Agroforestry Center | Ouedraogo S.J.,Institute du Sahel INSAH
Current Opinion in Environmental Sustainability | Year: 2014

In the Sahelian zone of West Africa, crops grown under a discontinuous cover of scattered trees dominate many landscapes and constitute the so-called parklands. These systems reflect the ecological knowledge of the farmers of such risk prone environments. Agroforestry parklands are playing an important role, through trees and shrubs providing soil cover that reduces erosion and buffers the impacts of climate change. They also provide green fodder that complements crop residues for livestock feeds, and fruits and leaves for human consumption and for income generation. The interactions between various components of the system influence the ecosystem service functions of trees of parklands (provisioning, regulating and supporting services) in several ways. These ecosystem functions have been at the center of the local ecological knowledge guiding the management options of the farmers and have also attracted the attention of scientists. Findings revealed new challenges that call for production options ensuring increased and diversified productivity of the systems while preserving the environment. Research on such challenges must adopt an inclusive approach based on local knowledge supported by science-based analyses of the socio-ecological systems in the face of high population pressure and climate change. © 2013 Elsevier B.V.

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