A preliminary checklist of the alien flora of Algeria (North Africa): taxonomy, traits and invasiveness potential.
Biological invasions are permanent threat to biodiversity hotspots such as the Mediterranean Basin. However, research effort on alien species has been uneven so far and most countries of North Africa such as Algeria has not yet been the subject of a comprehensive inventory of introduced, naturalized and invasive species. Thus, the present study was undertaken in order to improve our knowledge and to propose a first checklist of alien plants present in Algeria, including invasive and potentially invasive plants. This work aims to make an inventory of all available data on the alien flora present in Algeria, and to carry out preliminary quantitative and qualitative analyses (number of taxa, taxonomic composition, life forms, geographical origins, types of habitats colonized, degree of naturalization). The present review provides a global list of 211 vascular species of alien plants, belonging to 151 genera and 51 families. Most of them originated from North America (31.3%) and the Mediterranean Basin (19.4%). Nearly half (43%) of alien species are therophytes and most of them occur in highly disturbed biotopes (62%), such as arable fields (44.5%) or ruderal habitats, including rubble (17.5%). Introduced plants for ornamental purposes account for almost half (43.6%) of the alien flora. A large proportion (51.2%) of alien species is naturalized in Algeria, with about 16% considered as invasive or potentially invasive. However, the actual impact of these alien species on plant communities and ecosystems deserves urgent assessment with specific studies on impact at the community and the ecosystem levels.