RT info:eu-repo/semantics/article T1 How do alien plants distribute along roads on oceanic islands? A case study in Tenerife, Canary Islands A1 Marrero Arteaga, Manuel Alejandro A1 Delgado, Juan Domingo A1 Otto, Rüdiger A1 Fernández-Palacios, José María A1 Arévalo, José Ramón K1 Roadside vegetation K1 Species richness K1 Aspect K1 Ordination K1 Climate matching K1 Tenerife K1 vegetación de los arcenes K1 diversidad de especies AB Islands are paradigms of the pervasivespread of alien plants, but little work has been doneassessing pattern and cause of the distribution of suchplants in relation to roads on oceanic islands. Westudied richness, composition, and distribution of alienplants and compared them with native species alongroads on Tenerife (Canary Islands).We studied a singleroad transect that sampled two contrasting wind-facingaspects (leeward versus windward) and ran fromcoastal Euphorbia scrubland through thermophilousscrubland to Makaronesian laurel forest at the top of amountainous massif. We evaluated the effects ofelevation, aspect, distance to urban nuclei, and severalroad-edge features (including road-edge width andmanagement—implying disturbance intensity), usingregression models, analysis of variance, and multivariateordination methods. Richness of both endemicsand native nonendemics was explained by elevation(related to well-defined vegetation belts), steepness ofthe edge slope, and cover of rocky ground. Despite ashort elevational gradient (0–650 m), we found clearaltitudinal zonation by biogeographic origin of bothnonendemic natives and aliens, and altitudinal distributionof aliens followed the same zonation as that ofnatives. Alien species’ richness was related to managementintensity determining edge disturbance, roadedgewidth, and distance to the nearest urban nuclei(propagule sources). Different variables explaineddistribution patterns of natives, endemics, and aliensalong roadsides on leeward and windward aspects.Altitude and aspect also had a strong influence on thefrequency of life strategies (woody species, annualsand biennial/perennial herbs) of roadside plant communities.Due to harsher environmental filtersoperating on the leeward aspect, alien species weredistributed along the altitudinal gradient in apparentconsistency with general biogeographical affinities.Tropical/subtropical taxa showed exponential decreasewith increasing elevation, Mediterranean taxa showeda unimodal response (i.e., maximum richness at midelevation, minimum at the extremes of the gradient),and temperate taxa showed linear increase withelevation. Native but nonendemic species followed analogous trends to those of aliens. This suggestsclimatic matching as a prerequisite for successfulinvasion of this topographically complex island. Otherroad traits, such as edge width, slope steepness, soilcover, and road-edge disturbance intensity may play acomplementary role, at a more local scale, to shape thedistribution of alien plants on these island roads. PB Springer International Publishing YR 2009 FD 2009 LK http://riull.ull.es/xmlui/handle/915/18355 UL http://riull.ull.es/xmlui/handle/915/18355 LA en DS Repositorio institucional de la Universidad de La Laguna RD 12-nov-2024