Hipótesis de Naturalización de Darwin evaluada en la flora exótica de Chile continental

Abstract

The Darwin's Naturalization Hypothesis (DNH) states that the successful naturalization of alien species is favored when the phylogenetic relationship between the colonizer and the recipient community is distant. Conversely, related species would compete strongly, hence reducing the probability of naturalization. From a populational perspective, the concept of naturalization involves both the progressive increase in size and spatial distribution of the invasive population. In this study, we focused our attention on the spatial component of naturalization, assessing the role of phylogenetic relatedness as a determinant of its extension. Following the DNH, it is expected that those alien species closely related to the native flora would show narrower distribution ranges than alien taxa less related to native species. Using the APG III taxonomic system as an indicator of phylogenetic relationships in the vascular flora of continental Chile, our analysis showed that alien species with congeneric native counterparts have larger ranges than alien species with a distant relationship (i.e. species belonging to families or orders not represented in the native flora). These results do not support the DNH because the more distant taxa (less related species) show distributional ranges smaller. Results suggest that close relatedness could have facilitated the naturalization of alien plants in continental Chile, at least for species belonging to genus and families represented on the native flora. © Sociedad de Biología de Chile.