Biological invasions are a major threat to biodiversity and create many social and economic problems. This research will study what controls plant invasions on an Argentinean island where a century ago 135+ exotic tree species were planted in large numbers. Among them were many species famous as invaders. Surprisingly few of these species have invaded native forest on this island. Preliminary observations and experiments suggest three likely, non-exclusive hypotheses for this dearth of invasion: absence of suitable mutualistic root-fungi, herbivory by exotic deer, and consumption of seeds by rodents. This project entails experiments and laboratory analyses to test these hypotheses. This research will use seeds planted in different locations with and without addition of mutualistic root-fungi, rodent exclosures, and preference experiments for both deer and rodents to see which factors explain the observed lack of invasion.
The 21st century is expected to bring one of the biggest losses of biodiversity this planet has ever seen. Invasive species, mostly assisted by humans, are one of the greatest threats to biodiversity and also produce huge economic losses. Therefore, to conserve biodiversity and manage exotic species effectively, it is crucial to understand the mechanisms regulating invasion; this is the goal of this study. In addition, this research will test various ecological hypotheses, which will contribute to the progress of ecological sciences, since introduction of a species constitutes a large-scale natural experiment.
