La variabilité de la pluviosité annuelle dans quelques régions arides du monde ; ses conséquences écologiques

Le degré d’aridité d’une région est généralement apprécié par la hauteur moyenne de ses précipitations annuelles ou par divers indices combinant celle-ci avec la température, l’évaporation ou l’évapotranspiration potentielle. Cette manière de faire paraît insuffisante car elle fait abstraction de l’important facteur d’aridité que constitue le degré de variabilité de la pluviosité. En effet il peut exister de très grandes différences de variabilité entre diverses régions climatiques ou écologi..

The Rangelands of the Sahel

This article is an attempt to review and synthesize the present state of knowledge on the Sahel rangelands in a concise way. Ecological conditions, land use practices, livestock numbers, and livestock production systems are briefly analysed. Range types, dynamics, production, development strategy, and outlook are also reviewed. The conclusion that emerges is that the Sahel should be kept as breeding ground and included in a livestock production stratification strategy which should also involve the higher potential zones further south in the Sudanian and Guinean ecological zones. Such a development stategy implies the improvement of the conditions of range utilization in the Sahel, in particular a better definition of basic resources ownership (range and water) as well as of the marketing and prices policies.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202