John Libbey Eurotext

Science et changements planétaires / Sécheresse

Environmental constraints and limits to livestock husbandry in arid lands Volume 17, issue 1, Janvier-Juin 2006

Author
327, rue de Jussieu, 34090 Montpellier France
  • Key words: arid zone, rangelands, animal husbandry, animal production, climatology
  • Page(s) : 10-8
  • Published in: 2006

Constraints to animal husbandry in arid lands are multiple and of a varied nature: political, sociological, economical, legal, environmental, and technical (management). Environmental constraints mainly pertain to water as a key issue in both primary and secondary production. But the water issue itself is a complex one as it is tightly related to radiation, actual and potential evapotranspiration, topography, surface hydrology, hydrogeology, wind, temperature, as well as to vegetation structure, composition and potential productivity. How to remove or mitigate those constraints is the science and art of management i.e. the manipulation of physical and biological parameters in order to optimize primary and secondary productivity and economic output. But socioeconomic conditions may interfere heavily with environmental constraints in either a positive or negative way, with respect to the overall output of the ecosystems on a sustainable basis. This paper defines arid lands, and considers rain use efficiency (RUE), water availability in time and space, insolation and wind and their respective roles in secondary productivity. It then addresses the problems of how to manipulate vegetation, herds/flocks and grazing in order to best overcome these constraints on a sustainable basis.