Structural vegetation types of riparian ecosystem in Oued El Kharouaa region of Setif.

Abstract

This study aimed to assess floristic diversity and vegetation structure in the riparian ecosystem of Oued El Kharouaa, located in the Sétif region of northeastern Algeria. This semi-arid riparian ecosystem plays an important role in riverbank stabilization, biodiversity conservation, and ecological connectivity. Field surveys were conducted between August and December 2025 across six sampling stations distributed along the longitudinal gradient of the wadi using a stratified random sampling design, with a total of 60 plots established to investigate tree, shrub, and herbaceous vegetation layers. The floristic inventory recorded 41 plant species belonging to 23 families, with Asteraceae representing the dominant family. Biological and chorological analyses revealed the predominance of therophytes and hemicryptophytes, reflecting adaptation to Mediterranean climatic conditions and anthropogenic disturbance. Floristic diversity, assessed using Shannon and Simpson indices, showed marked spatial variation among stations and vegetation strata, with the herbaceous layer exhibiting the highest diversity values, whereas shrub communities displayed lower diversity and stronger species dominance. Among woody species, Populus alba was identified as the most frequent tree species within the study area. Vegetation