Floristic diversity and distribution patterns along a salinity gradient in three Ramsar wetlands in Northeastern Algeria

Abstract This study investigates the floristic, biological, and chorological diversity of three Ramsar wetlands in the Sebkhetes of Aurès Wetlands Complex (SAWC) Algeria: Garaet Timerganine (freshwater), Chott Tinsilt (brackish water), and Sebkhet Ezzmoul (saline water). 154 taxa were recorded during field surveys. Asteraceae, Poaceae, and Fabaceae were the most represented families. Total taxa richness, Shannon diversity index (H′) and Pielou’s equitability (E) showed relatively high values at Garaet Timerganine (S = 78, H’ = 5.07, E = 0.82) and Sebkhet Ezzmoul (S = 52, H’ = 5.38, E = 0.94), while Chott Tinsilt (S = 63, H’ = 4.43, E = 0.73) exhibited moderate diversity with strong floristic homogeneity. The flora was predominantly composed of therophytes (48%) and hemicryptophytes (37 %), reflecting adaptations to salinity variability. Chamaephytes (9%), Geophytes (3%), Nanophanerophytes, Microphanerophytes and Phanerophytes were present in meaningfully lower proportions (1%). The chorology of recorded flora was dominated by the Mediterranean set encompassing 74 taxa, which constitutes 48.07% of the total flora. Species with a wide distribution set accounted for 56 species (36.30%), while the Northern set had a notable presence with 23 species (15%). Limonium pruinosum (Plumbaginaceae) was the only Saharan species exclusively recorded in Sebkhet Ezzmoul. Using Correspondence Factor Analysis (CFA), species distribution patterns were clearly aligned along a salinity gradient. Garaet Timerganine was associated with mesophilous taxa, Chott Tinsilt with stress-tolerant brackish species, and Ezzmoul with halophytes ones. This study highlights the fact that salinity shapes floristic diversity and guides adaptive wetland management in arid regions.