Plant Diversity and Sustainable Development in the Wadi Al-Washka Dam Area, Libya

Abstract

Drylands cover nearly half of the Earth's land surface and rank among the ecosystems most vulnerable to climate change and human pressure, yet the central Saharan sector of Libya remains almost entirely undocumented floristically. This study inventoried and assessed the vascular plant diversity of the Wadi Al-Washka dam area in the Al-Jufra region of central Libya and examined its significance for sustainable development. A descriptive–analytical approach was adopted; field data were collected across the autumn (November 2025) and spring (April–May 2026) seasons using twenty-four 1 × 1 m quadrats, in which species were identified, their names updated against POWO and WFO, and life-forms, chorotypes, relative importance values (RIV) and diversity indices computed on both cover and density bases. A total of 33 vascular plant species belonging to 29 genera and 18 families were recorded, dominated by Asteraceae and Poaceae (15.2% each), with a high proportion of monospecific families (55.6%). Chamaephytes prevailed in the life-form spectrum (45.5%), and the Saharo-Arabian element dominated the chorological structure (about 41% alone). Cover-based diversity (Shannon H′ = 1.88; Simpson 1 − D = 0.79; Pielou J′ = 0.54) revealed a numerically balanced community subject to spatial dominance by a few water- and salinity-associated species—Tamarix sp., Pluchea dioscoridis, Phragmites australis and Pulicaria undulata—reflecting the hydrological influence of the dam. The study provides the first quantitative floristic baseline for the area and recommends a continuous, multi-year programme to monitor evaporation-driven secondary salinity and its direct effect on vegetation structure, alongside sustainable rangeland management, thereby supporting desertification monitoring, land-degradation neutrality and biodiversity conservation in this fragile desert environment.