The Impact of Exclosure on the Rehabilitation of Steppe Vegetation at Naâma Rangelands in Algeria

The Naâma steppe rangelands in Algeria are undergoing continuous degradation due to overgrazing, land clearing, silting up and desertification. Given the seriousness of this situation and the ecological deterioration of these steppe rangelands, the need for an action plan to preserve and rehabilitate the degraded rangelands is becoming more and more urgent. Among the solutions proposed for the degraded rangeland rehabilitation, the exclosure has proven to be an effective and inexpensive fight against the degradation factors. This study aimed to quantifying the effectiveness and impact of the exclosure rehabilitation technique after a protection period (2009-2015) in the esparto grasslands (Stipa tenacissima L.) ranges located at Djedida in the Naâma region (Western Algeria). The adopted methodological approach is that of the comparative analysis of vegetation descriptors based on a quantitative (recoveries, floristic richness) and qualitative assessment, evaluation of the plant cover (biological, systematic, biogeographic phytodiversity) between the exclosure rangeland and the nearby located grazing rangeland having about the same climato-edaphic station conditions. Thirty phytoecological surveys were carried out for the exclosure rangeland as well as on an unprotected control range (outside the exclosure area). The comparative analysis of the obtained results shows that, in general, the exclosure rangeland is relatively much richer in terms of quantity and quality than the grazing range. In the exclosure areas, the vegetation was more productive and more diversified, the average vegetation cover was 25% vs 5%, Number of species was 41 vs. 14 and density was 19.3 vs, 4.6 plants/100m² for exclosure and open grazing range, respectively. On the other hand, in the grazing range, the vegetation was much diversified in terms of biological, systematics and biogeographic aspects in terms of floristic diversity. The impact of exclosure of pastoral improvement was interesting after a period of more than 6 years.