Végétation et cartographie des mares temporaires du Sétifois (Nord de l’Algérie)

Abstract

The main objective of our study is to inventory the flora of the temporary ponds in the Sétif region and to establish a diagnosis of their current state, in order to analyze their diachronic evolution and assess changes in land use. This work is also complemented by a socio-economic survey conducted among the local population to understand the human–pond relationship. The floristic inventory recorded 139 species, distributed across 87 genera and belonging to 35 botanical families, with a strong dominance of the Poaceae family (19 species). These species are either restricted to wetland habitats or associated with terrestrial environments. The analysis of the overall biological spectrum revealed a predominance of hemicryptophytes (70 species, representing 50%). Most of the recorded species belong to the northern phytochoric group (37%), while ten species are endemic. Moreover, among the 139 inventoried species, 10 are considered rare, and another 10 are listed among Algeria’s protected wild plant species. Some species that had previously only been reported in Numidia, such as Elatine alsinastrum L. and Isoetes longissima Bory & Durieu, were observed for the first time in the region. The study also identified 18 medicinal species. The diachronic analysis, covering the period 2010–2023, highlights a significant regression in the surface area of certain ponds, such as Oum Lamouadjne pond, which decreased from 11840.28 m² en 2010 to 8329.805 m². This decline is a direct consequence of human practices such as agriculture, grazing, drainage, filling, trampling, livestock watering, and pollution. Land-use changes in the communes of Aïn Abbessa and Aïn El Kebira show both a decrease and, in some cases, an increase in pond surface area. This dynamic is mainly explained by recurrent droughts and climate variability, which reduce flooding duration, as well as anthropogenic pressures, including urbanization and agriculture, which lead to the alteration or disappearance of certain sites. The diachronic analysis of the NDWI index in these regions (2007–2025) confirms a progressive reduction in water surfaces. The socio-economic survey reveals that the ponds are resource-rich ecosystems providing multiple services to local populations, including grazing, agriculture, water supply, and medicinal plants. However, perceptions of these environments are strongly influenced by land tenure: most users, being private landowners, consider the ponds as open-access resources, which increases their vulnerability to anthropogenic pressures and climate change. This highlights the urgent need to implement conservation measures and to develop legislative frameworks aimed at ensuring the sustainable protection of these fragile ecosystems.