RT info:eu-repo/semantics/article T1 Distribution of alien vs. native plant species in roadside communities along an altitudinal gradient in Tenerife and Gran Canaria (Canary Islands) A1 Arévalo, José Ramón A1 Delgado, Juan Domingo A1 Otto, Rüdiger A1 Naranjo, Agustín A1 Salas, Marcos A1 Fernández-Palacios, José María K1 Alien species K1 Altitudinal gradient K1 Disturbance K1 Invasive plants K1 pDCCA K1 Quadratic regression AB Roadside plant communities were studied along two roads following an altitudinal gradient in Gran Canaria andTenerife (Canary Islands). Our aim was to investigate variation in plant species richness, particularly of the alien flora,along a gradient from coastal shrubland to summit vegetation (1950m a.s.l. in Gran Canaria, 2300m in Tenerife) inrelation to variation in habitat factors (altitude, habitat structure, roadside disturbance, distance to urban nuclei). Wecompared different species groups that were classified in terms of their biogeographical status, origin and life form.Altitude was the most important factor determining species richness and composition along both roadside transects.Alien plants showed a unimodal distribution pattern along the altitudinal gradient, with less species and lowerabundance at low and high altitudes, and highest abundance at intermediate altitude. Alien plant species were alsorelatively more frequent near urban centres. The number of native and alien species was significantly positivelycorrelated along the altitudinal gradient. Both alien and native, non-endemic species showed differences in theirdistribution along the altitudinal gradient according to their biogeographical affinities and climatic tolerances. Despiteconsiderable differences in species pools these patterns were consistent among the two islands. Environmental (abiotic)stress is proposed as a primary, altitude-related factor acting as a filter against most alien plants at coastal and highmountainaltitudes. A higher frequency or intensity of disturbance at intermediate altitudes may be a further causalfactor promoting alien plants in this zone. Future management efforts to control alien plants along roads should,therefore, concentrate on intermediate altitudinal zones of the higher Canary Islands. PB Elsevier YR 2005 FD 2005 LK http://riull.ull.es/xmlui/handle/915/17924 UL http://riull.ull.es/xmlui/handle/915/17924 LA en DS Repositorio institucional de la Universidad de La Laguna RD 29-mar-2024