GRAZING EFFECT ON FLORISTIC DIVERSITY AND STRUCTURE IN ARID RANGELANDS OF ALGERIA.

Land degradation is a global issue affecting environment around the world, when occurring in arid and semiarid environment this phenomenon is defined as desertification. Overgrazing can generate a regressive chain reaction leading to degradation of vegetation cover and loss of biodiversity. The use of indicators to assess desertification is suitable to detect the state of the health of rangeland ecosystems. In this study, we assessed species richness and diversity between two habitats (grazed and ungrazed), in addition, we evaluated the effect of grazing on the total vegetation cover, bare ground cover and co-occurrence between the two treatments. Our results indicated that richness, diversity, total vegetation cover and co-occurrence were affected by grazing activity. The high value of bare ground cover indicated a regressive trend, which can be interpreted as a process of desertification. However, the protection from grazing promoted vegetation cover and diversity. It is recommended to use controlled grazing and increase protected zone areas.