Do alien and native tree species from Central Argentina differ in their water transport strategy?

Abstract

In this study we assessed the water transport strategies and the abundance of alien and native tree species at a regional scale in Córdoba Mountains, Central Argentina. The aims of this study were: 1) to analyze whether alien and native tree species show divergent water transport strategies; and 2) to explore whether species abundances of alien and natives are associated with specific trait attributes. Eight alien species and 12 native species were recorded in 50 complete vascular plant vegetation relevés. Water transport strategies were assessed through the following functional traits: minimum leaf water potential, potential water content of wood, effective leaf area, leaf area per sapwood area, and wood density. Also, resource use strategies were assessed throughout the measurement of specific leaf area. We found that alien species had a higher efficiency in water transport (i.e. higher minimum leaf water potential and lower wood density values) and faster resource acquisition and use (higher specific leaf area values) than native species. We did not find evidence suggesting that the relative abundance of species was associated to water transport strategies and faster resource acquisition and use. Alien species seem to differ from natives in specific functional attributes that are absent in the resident community and might allow aliens to use more resources and at a higher rate than native species. Finally, our results show the potential of a trait based predictive framework for alien species, and the possible effects on ecosystem functions.