The endemic vascular plant species of Egypt: distribution patterns and implications for conservation

Taxa endemic to a country are the most valuable component of flora and deserve high regional and global conservation priorities. Due to their restricted distribution, endemic taxa may be intrinsically threatened and are therefore highly important in the local prioritization of conservation efforts. In Egypt, the number of exclusive endemic vascular plants, their distribution pattern and conservation assessment are out of date or unknown. The aims of this research project were (1) to build an updated checklist of the endemic vascular flora of Egypt, (2) to evaluate possible species shift according to climate change of a selected set of vascular plant species of particular interest (e.g. Rosa arabica), (3) to recognize the biogeographical patterns in Egypt based on presence of endemic flora together with environmental features, and (4) to apply methods of species distribution modeling in order to guide the discovery of new localities for rare endemic vascular plants in South Sinai, Egypt. The first results showed that Egypt hosts 48 endemic taxa belonging to 42 genera, 18 families and representing 2.3% of the total flora. The most represented families are Asteraceae, Lamiaceae, and Caryophyllaceae, while the most represented genus is Silene (three endemic taxa). The richest regions in Egyptian endemic taxa are Southern Sinai (14 taxa), Northern Sinai and Matrouh (12 taxa each). Depending on the first findings, the biogeographical approach of Egypt was carried out by using K-nearest neighbors in the ArcGIS environment and 11 environmental factors. Egypt was classified into 15 environmental clusters, which were clustered in six biogeographical sectors and nine subsectors, determined according to the presence/absence of 140 endemic taxa. The highest endemic richness was recorded in the Marioutico- Arishian (71 species), Sinaitico- Arabian (62 species) and Nilotic (16 species) sectors, and in Sinaitico (54 species), Arishian (45 species) and Marioutico (40 species) subsectors. Nonetheless, the most protected sectors were Elbanian and Suezian (62.73 and 29.05%, respectively) while the lowest sectors were Nilotic and Marioutico- Arishian (9.86 and 13.26%, respectively). The already established protected areas in Egypt are not sufficient for conserving the identified endemic rich plant sectors. Concerning current and future potential distribution of Rosa arabica, annual temperature, elevation, and annual precipitation were the key factors for its distribution. The simulation outputs of R. arabica models under two future climate change projections displayed a range contraction through gains in unsuitable habitats and losses in highly suitable habitats. Finally, the current potential distribution of Primula boveana Decne. ex Duby, critically endangered taxon was carried out by the MaxEnt model. The majority of suitable habitats were located in the high elevated middle northern part of the St. Catherine area. After a set of field trips to all predicted potential distribution sites at high elevated sites near water springs, unfortunately, we did not find any new populations but we discovered five extinct localities where P. boveana were completely disappeared. Species distribution models cannot replace field surveys that proposed to collect distribution data but can be a valuable tool to improve data investigation. Such preliminary results, as well as the entire thesis, will represent a tool for providing a framework for research, protection and policy implementations for these endemic taxa and threatened habitats.