TY - GEN A1 - Galán Díaz, Javier A1 - Garcia de la Riva, Enrique A1 - Parker, Ingrid M. A1 - Leiva, María José A1 - Bernardo-Madrid, Rubén A1 - Vilà, Montserrat T1 - Plant Community Assembly in Invaded Recipient Californian Grasslands and Putative Donor Grasslands in Spain T2 - Diversity N2 - The introduction of exotic species to new regions offers opportunities to test fundamental questions in ecology, such as the context-dependency of community structure and assembly. Annual grasslands provide a model system of a major unidirectional introduction of plant species from Europe to North America. We compared the community structure of grasslands in two Mediterranean regions by surveying plots in Spain and in California with similar environmental and management conditions. All species found in Spanish grasslands were native to Spain, and over half of them (74 of 139 species) are known to have colonized California. In contrast, in California, over half of the species (52 of 95 species) were exotic species, all of them native to Spain. Nineteen species were found in multiple plots in both regions (i.e., shared species). The abundance of shared species in California was either similar to (13 species) or greater than (6 species) in Spain. In California, plants considered pests were more likely than non-pest species to have higher abundance. Co-occurring shared species tended to maintain their relative abundance in native and introduced communities, which indicates that pools of exotic species might assemble similarly at home and away. These findings provide interesting insights into community assembly in novel ecosystems. They also highlight an example of startling global and local floristic homogenization. KW - biogeographical comparisons KW - community similarity KW - exotic plants KW - Mediterranean grasslands KW - pests KW - plant invasions KW - species abundance Y1 - 2020 U6 - https://doi.org/10.3390/d12050193 SN - 1424-2818 VL - 12 IS - 5 ER - TY - GEN A1 - Galán Díaz, Javier A1 - Vilà, Montserrat A1 - Parker, Ingrid M. A1 - Garcia de la Riva, Enrique T1 - Functional assembly of grassland plant species in native communities in Spain and recipient communities in California T2 - Journal of Ecology N2 - A major aim in invasion ecology is to understand the role of exotic species in plant communities. Whereas most studies have explored the traits of exotic species in the context of the introduced community, functional comparisons of entire assemblages of species in their native and introduced communities have rarely been analysed. Taking advantage of the unidirectional invasion of plant species of European origin (i.e. colonizers) into California, this study aims to investigate the relative importance of plant traits, environmental factors and invasion status in biological invasions.We compared the functional structure (i.e. trait composition and diversity) along resource availability gradients in recipient and native Mediterranean grassland communities in California and Spain, respectively. Traits were related to resource use in above-ground and below-ground organs and reproductive strategy. We also investigated how niche differences vary along environmental gradients between coexisting colonizer and native species assemblages within communities.There were clear differences in the functional structure of Mediterranean grassland communities between regions, which were associated with the resource availability gradient. Paradoxically, the most acquisitive communities occurred in resource-poor sites, highlighting that rapid acquisition and use of resources permit species to cope with environmental stress through stress avoidance. In Spain, colonizer species had greater specific leaf area than non-colonizers. Yet, differences between colonizer and non-colonizer species in Spain for other traits were mostly absent and did not change along the gradient. This might be a result of the greater native species richness as a consequence of the agricultural practices that have taken place in Europe for millennia and reflect that the entire species pool of grasslands is adapted to agricultural landscapes. In comparison, in California, colonizer species were more acquisitive in their use of resources than natives under favourable conditions, but functionally converged in resource-limited sites.Synthesis. These results underscore that the importance of niche differences between native and colonizer species as a community assembly mechanism is strongly subjected to the influence of habitat filtering. Trait comparisons are context dependent, and a correct interpretation of filtering processes in community assembly requires a regional perspective. Y1 - 2022 U6 - https://doi.org/10.1111/1365-2745.14027 SN - 0022-0477 VL - 111 IS - 1 SP - 214 EP - 226 ER -