DYNAMIC OF PLANT COMMUNITIES IN SAHARAN RANGELANDS OF TUNISIA
The desert and Saharan rangelands of southern Tunisia are an important source of feed for grazing herds. Productive management of these rangelands has been found impossible if the natural vegetation becomes severely degraded unless restoration work is undertaken. The main objective of our study was to evaluate the impact of protective fencing for periods of one, two and three years duration on Saharan vegetation at three sites characterised by sandy and limestone (skeletal) soils. Results showed that vegetation covering, measured in terms of species richness and plant biomass, increased with time of protection from grazing, and that covering was more marked on the sandy substrate than on the limestone substrate, while under heavy grazed area the opposite occurred, thus I can deduce that the sandy soil are more productive than the limestone soil, whereas the latter are more resistant to animals trampling.