Article

The Mediterranean coastal land is one of the richest phyto-geographic territories of Egypt owing to its relatively high rainfall. Sallum sector is situated in the Libyan-Egyptian border. This study deals with, the vegetation covers in different habitats, floristic composition, species richness, species diversity, and chorotypes in Sallum sector. The current floristic composition was compared to that from the last ten decades, to elucidate: the past-present and the future vegetation trend; the change in floristic composition through these decades; trace the impact of climatic changes represented by temperature and rainfall. And, trace the desert expansion as the spatial distribution of the SaharoSindian chorotype. The combined dataset has demonstrated a poleward species sift, notable differences in their response to shortage in rainfall and increased temperatures, were observed among the recorded chorotypes and the species composition across studied habitat range. The SaharoSindian chorotype showed poleward expansion. The retrieved data including, a decline in the total number of the recorded species, changes in their distribution range, recording the timing erosion and the northward expansion of some indicator species. The decline in mean annual rainfall was inconsistent with positive shift in the mean maximum temperature with 1.5˚C. Northward expansion of xerophytes and loss of species diversity through the studied successive decades. Such study provides a case study for the effect of climatic changes in arid land, to support the climatic scenarios. Finally, urgent need of conservation effort and mitigation measures to control the genetic erosion in such arid coastal sector.