Anthelme Fabien auteur aut IRD Wasiri Mato M. auteur aut IRD Maley Jean auteur aut IRD text journalArticle eng text/pdf born digital access The inselberg structure and the local habitats of the Air mountains (Niger) are hypothesized to generate the coexistence of geographically isolated plant species with high conservation values. By studying the diversity and the distribution of plants on the highest peak of these mountains, we aimed to identify the respective effects of local and regional abiotic factors on isolated species. We estimated the regional effects of elevation by comparing 103 floristic quadrats with existing data in the adjacent lowlands, and we tested the effects of local abiotic variables on species distribution with ordination methods. Among the 151 species identified, 12 were recorded for the first time in Niger and 53 were not found in the adjacent lowlands, thus evidencing true mountain specificity. A five-class habitat variable separated a relatively high portion of Saharan-Mediterranean species (8%) located in volcanic gullies, and Guinean-Sudanian-Zambezian species (13%) located in granite boulders. These two habitats provided local abiotic refuges (boulders, gullies), which protected a pool of relictual species from aridity, and probably from grazers. Species persistence may thus be dependent both on regional and local abiotic variables. With probable high genetic divergence because of the surrounding desert matrix, their conservation value may be particularly high. specialized Conservation Desert Granite boulders Inselberg Isolation Volcanic gullies NIGER SAHARA 082 72 12 2232-2242 2008 0140-1963 https://www.documentation.ird.fr/hor/fdi:010044091 10.1016/j.jaridenv.2008.07.003 0140-1963 [F B010044091] https://www.documentation.ird.fr/hor/fdi:010044091 https://www.documentation.ird.fr/intranet/publi/2008/12/010044091.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2009-01-09 2022-07-04 fdi:010044091 fre