CONICET | Buscador de Institutos y Recursos Humanos

Invasive plant species are a growing concern in many regions of the world, yet little information isavailable on the effects of habitat type and distance to urban settlements on the ability of alien plants tobecome established. We studied plant communities from the arid steppes to the Andean forest withintwo national parks and surroundings, in northwestern Patagonia, Argentina. Alien and native vascularplant species were sampled using 90 100 m2 plots and analyzed in relation to both climatic andenvironmental variables and distance to urban centres. We also compared life-forms of alien and nativespecies. Precipitation and distance to an urban centre were important determinants of alien speciescommunity richness and composition, and shrubland sites had significantly more alien species thanforest or steppe sites. Alien flora (15% of the species) was composed of a higher proportion of annuals andbiennials than native flora. Our results suggest that precipitation, distance to source population, andanthropogenic disturbance influence the invasion process in this region, together with the availability ofopen niches. This work stresses the importance of monitoring invasive species in natural reserves, and ofconsidering habitat types as well as idiosyncratic characteristics of the non-natives for developingmanagement strategies.