Inaccessible zones of Jabal Salma, Ha'il region in Saudi Arabia: a reservoir for native seed species.
A reservoir in the current study describes where endemic plants are most likely to thrive and provide natural gene bank for native seed species. Twelve sites representing different altitudinal zones of Jabal Salma in Ha'il region, Saudi Arabia were regularly visited for two consecutive years. From each site 2-5 locations were investigated for floristic composition and types of vegetation. During the study, the presence of total 150 species representing 39 families was recorded. Among the reported species, the highest number of species (25 species) were belong to the family Asteraceae which was followed by the family Brassicaceae, (17 species), Fabaceae (14 species), Boraginaceae (11 species), Caryophyllaceae (10 species) and finally Poaceae (9 species). However, 15 other families including Acanthaceae, Convolvulaceae, Moraceae, Nyctaginaceae and Primulaceae, were monospecific which represented by only a single species. In addition, the effect of elevation on plant species distribution along altitudinal gradient of Jabal Salma has been noticed clearly in this study. According to the current findings, Jabal Salma can be strongly considered as a reservoir for native seed species as it provides refuge for 21 endangered species, 43 medicinal species, 45 ornamental species, 48 forage species and 13 edible species. However, despite accessibility difficulties, Jabal Salma "unfortunately" is not well protected against invasive species where 27 exotic species where recorded.