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Desertification, Adaptation and Resilience in the Sahel: Lessons from Long Term Monitoring of Agro-ecosystems

  • Pierre HiernauxEmail author
  • Cecile Dardel
  • Laurent Kergoat
  • Eric Mougin
Chapter
Part of the Springer Earth System Sciences book series (SPRINGEREARTH)

Abstract

The desertification paradigm has a long history in the Sahel, from colonial to modern times. Despite scientific challenge, it continued to be influential after independence, revived by the dramatic droughts of the 1970s and 1980s, and was institutionalized at local, national and international levels. Collaborative efforts were made to improve scientific knowledge on the functioning, environmental impact and monitoring of selected agricultural systems over the long term, and to assess trends in the ecosystems, beyond their short term variability. Two case studies are developed here: the pastoral system of the arid to semi-arid Gourma in Mali, and the mixed farming system of the semi-arid Fakara in Niger. The pastoral landscapes are resilient to droughts, except on shallow soils, and to grazing, following a non-equilibrium model. The impact of cropping on the landscape is larger and longer lasting. It also induces locally high grazing pressure that pushes rangeland resilience to its limits. By spatial transfer of organic matter and mineral, farmers’ livestock create patches of higher fertility that locally enhance the system’s resilience. The agro-pastoral ecosystem remains non-equilibrial provided that inputs do not increase stocking rates disproportionately. Remote sensing confirms the overall re-greening of the Sahel after the drought of the 1980s, contrary to the paradigm of desertification. Ways forward are proposed to adapt the pastoral and mixed farming economies and their regional integration to the context of human and livestock population growth and expanding croplands.

Keywords

Sahel Desertification, ecosystem resilience Pastoral management Non-equilibrium dynamics 

Notes

Acknowledgements

The authors are indebted to many colleagues and collaborators for the data collected and analysed over several decades both in Mali and Niger under a series of research projects and funding agencies listed in the endnotes. Among them they would particularly like to thank the main actors of the long term monitoring and production system studies: late Mohamed Idrissa Cissé, late Lassine Diarra, Youssouf Maiga and Nogmana Soumaguel in Mali, Adamou Kalilou, Oumar Moumouni and Seybou Garba in Niger. Among the colleagues whose works were particularly useful in this chapter, the authors would like acknowledge the works of Matthew Turner from University of Wisconsin, Augustine A. Ayantunde from ILRI, Manuela Grippa from the GET laboratory in Toulouse, Valérie Trichon from the University Paul Sabatier in Toulouse. The remote-sensing analyses are borrowed from Cécile Dardel PhD thesis and Mamadou Diawara contributed to the results on the livestock impact. The authors are grateful to Layne Coppock for his thorough review and to Mike Mortimore who has kindly edited the text in proper English. This publication was made possible through the support provided by the research project ‘Environmental and social changes in Africa: past, present and future (ESCAPE, ANR-10-CEPL-005) funded by ANR (French National Research Agency).

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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Pierre Hiernaux
    • 1
    Email author
  • Cecile Dardel
    • 1
  • Laurent Kergoat
    • 1
  • Eric Mougin
    • 1
  1. 1.Geoscience Environment Toulouse (GET)ToulouseFrance

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