LAUSR

Abstract About a quarter of the world's plant species is under threat of extinction and depletion, often due to accelerated human activity, in addition to impacts of climatic changes. In order to preserve plant species against the extinction risk and keep for biodiversity, detailed knowledge about the requirements of plant habitats, as well as, the identification of most endangered sites should be determined, and the possible plants conservation means should be planned. Using accurate modeling for the distributions of plants is important in different applications of plant conservation and the environment. In the current study, Ebenus armitagei and Periploca angustifolia were selected as a study targets because they were classified as endangered species. In the current study, a model has been developed to estimating endangered plants distributive areas in Wadi Al-Afreet area. The selected plant species are, expected to disappear. The suggested model is based on finding the links between known botanical phenomena and the environmental variables. The model used leads show the distribution of environmental variables (i.e absolute and relative cover and density, height and diameter) of the two endangered species. It helps also too understand the soil impacts on plant distribution, thus some soil parameters (Total Dissolved Solids TDS), cations (Na+, K+, Ca+2 and Mg+2), pH, sand and silt + clay) were analyzed. The used model allows to predict the sites where the two endangered plants are expected to disappear along wadi Al-Afreet. The results showed that most threatened locations for Ebenus armitagei were predicted in the South-Eastern part of wadi Al-Afreet and the eastern part of midstream whereas the west-south part including upstream and midstream parts are less affected. The most threatened locations for Periploca angustifolia were predicted in the midstream part of wadi Al-Afreet whereas the upstream part had the least effects. Downstream location appeared ideal for P. angustifolia distribution. Results showed that the most important plant and soil characteristics that affected and controlled the distribution of plants and vegetation coverage structure in Wadi Al-Afreet are Total Dissolved Solids (TDS), silt and clay, pH and Mg+2. The model can help in setting priorities for plants to restore their natural habitat for more effective plant conservation and restoration.