The purpose of this study was to provide an inventory and an analysis of plant species occupying Beni-Haoua, a mountainous coastal ecosystem, with a rarely studied well-developed forest. As a result, 87 species were recorded in 7 sites, the Jaccard classification resulted in 4 groups of sites with significantly different diversities. According to the ϕ-coefficient of association, which can be used as a measure of fidelity, among the 87 species, 34 diagnostic species were distributed over four plant communities, with a fidelity value ranging from 55 to 100%, 28 differential species, among which 16 species were common to 2 plant communities and 12 common to 3 plant communities. The redundancy analysis (RDA) showed that among the studied environmental variables, altitude and pH were the most important ones. Indeed, according to the detrended correspondence analysis (DCA), plant species occurrence and distribution in the study area were affected by a strong altitudinal gradient.

The Simplified Surface Energy Balance Index (S-SEBI) algorithm was used in this study with four Landsat-5 Thematic Mapper images to assess the evapotranspiration (ET) in Bissa forest, one of the healthiest Algerian forests located south of the Mediterranean Sea. Results showed that ET varies over the different seasons, the highest ET values were reached during the spring due to water availability, whereas, the lowest values were recorded during the summer. The relationship between normalized difference vegetation index (NDVI) and ET showed that the highest ET values coincide always with the highest NDVI except for January where even the lowest NDVI values correspond to higher ET. The intensity of ET was closely related to aspects, southeastern exposures showed the highest ET, whereas, northwestern exposures showed the lowest ET.