Land use and beyond: unraveling environmental determinants of odonate assemblages in northeastern Algeria

Abstract

Freshwater ecosystems, recognized as hotspots of biodiversity, are under increasing threat from human activities. Odonata, the iconic inhabitants of these ecosystems, are highly sensitive to changes in habitat morphology, hydrology and land-use dynamics. In this study, the odonate assemblages in four different regions in northeastern Algeria are investigated to identify the key environmental factors that influence them. These regions differ in terms of climate, altitude and land use. Over the course of the study, we documented twenty-one species, including ten Zygoptera and eleven Anisoptera, which together account for a substantial proportion (~47%) of regional odonate diversity. Species composition is correlated with habitat typology and land cover. Multivariate analyses revealed distinct ecological patterns, highlighting streambed width, flow velocity and, to a lesser extent, land cover and altitude as influential factors in assemblage segregation. This study underscores the importance of flow velocity, which is known to facilitate oxygen uptake by larvae and influence the distribution and composition of species. Altitude, a key factor influencing phenology, growth and development, and land use (including forests, urbanization, agriculture and pasture) are also identified as potential determinants of odonate assemblages. To effectively tailor conservation strategies to specific regional conditions around the world, the study emphasises the importance of identifying the key environmental factors affecting odonate assemblages.