期刊名称：Science et changements planétaires / Sécheresse
印刷版ISSN：1147-7806
电子版ISSN：1777-5922
出版年度：1990
卷号：1
期号：4
页码：246-259
出版社：John Libbey Eurotext
摘要：Author Henri-Noël Le Houérou CNRS/CEFE, Centre d’Ecologie Fonctionnelle et Evolutive BP 5051, 34033 Montpellier Cedex 01, France Page(s) : 246-59 Published in: 1990 The Sahara occupies an area of some 8 million km2, below the 100 mm mean annual rainfall isohyet. This area corresponds with a maximum N-S distance of 2 000 km between Biskra and Agadès and some 5 500 km from E to W between Port Sudan and Nouadhibou along the 20°N. The Sahara offers a great bio-climatic diversity; there are a Mediterranean Sahara to the North, a Tropical Sahara to the South, a Central Plains Sahara, a Montane Sahara and an Oceanic Sahara. All these zones are perfectly well defined both in terms of climatic variables (rainfall, energy budget, evaporation, temperatures, etc.) and biological diversity. Plant distribution (2 800 species of flowering plants) and animal (300 vetebrates: 110 mammals, 100 birds, 100 reptiles, 20 fishes and 10 species of amphibians). Distribution patterns are tightly linked to climatic variables, particularly on the amount and seasonal distribution of rainfall and of temperatures. The latter may play as important a role as the former in animal and plant distribution since Mediterranean species may dominate in higher elevations under the tropic, whereas tropical species may intrude far into the Mediterranean zone wherever winter temperatures are mild.
