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：2007
卷号：18
期号：4
页码：240-245
DOI：10.1684/sec.2007.0108
出版社：John Libbey Eurotext
摘要：Figures See all figures Authors Mohamed Tarhouni , Farah Ben Salem , Azaiez Ouled Belgacem , Belgacem Henchi , Mohamed Neffati Institut des régions arides (Ira), Laboratoire d’écologie pastorale, 4119 Médenine, Tunisie, Faculté des sciences, Campus universitaire, 2092 Tunis, Tunisie Key words: animal pressure, arid zone, floristic composition, grazing, rangeland, Tunisian steppe, vegetal resources, watering point DOI : 10.1684/sec.2007.0108 Page(s) : 240-5 Published in: 2007 In collective rangelands, especially during the dry season, grazing activity is conditioned by the availability of watering points. Around wells there is a zone of extreme degradation where vegetation cover completely disappears as the result of intense animal pressure which affects the physical substratum and vegetation cover simultaneously. It is within this context that our study was carried out. Its main objective was to show the effect of the grazing gradient, simulated by the distance around three watering points located in the El Ouara region (southern Tunisia), on the biovolume of the most dominant species. For this purpose we measured the largest and smallest diameters as well as the heights of corresponding tufts at different distances around the wells. Main results show that the biovolume of each species decreases with the grazing gradient.
关键词：animal pressure; arid zone; floristic composition; grazing; rangeland; Tunisian steppe; vegetal resources; watering point
