Evaluation by prediction of the natural range shrinkage of Quercus ilex L. in Eastern Algeria

This study focuses on the evaluation by prediction of the spatial distribution of Quercus ilex. L in its natural range in Eastern Algeria. The maximum entropy method has allowed the modelling of the species potentially favourable areas under environmental conditions linking the spatial occurrence and the environmental conditions. Three explanatory parameter groups were used for modelling: i) Edaphic variables, ii) Variables related to topography, iii) Climatic variables. The established predictions demonstrate that over the horizons 2050 and 2070, we will lose 125000 and 147000 hectares respectively. It would seem that the most favourable areas for Quercus ilex would extend between elevations of 1430 meters for 2050 and reach by 2070, 1650 meters. The performance of the used model has been confirmed by the value of AUC which is 0,929. The high elevations especially those of the Saharian Atlas will offer the climatic refuges. These results represent a decision support tool for the best strategy of sensibilization and planning for the holm oak conservation.