Multi-level impacts of introduced wild boar on Patagonian ecosystems

Biological invasions are a pervasive global change that threatens biodiversity and the functioning of natural ecosystems, yet most studies focus on population impacts. Furthermore, the effects of invasive species on ecosystems are greatest when they introduce a novel disturbance. In this dissertation I reviewed the impact of wild boar (Sus scrofa) on native communities worldwide, identifying research needs. Wild boar overturns extensive areas of vegetation to feed on belowground plant parts, insects and fungi, thus altering native ecosystems integrity. By means of observational and experimental studies I addressed some of the research gaps on the impact of wild boar invasions on native communities and ecosystem functioning in Patagonia, Argentina. I evaluated the impact of wild boar on native plant community composition and structure, on soil properties, and on facilitating further invasion. I found that wild boar significantly alters aboveground ecosystem properties by reducing plant biomass and altering plant community composition. Furthermore, wild boar rooting disturbance significantly reduce litter decomposition rates, while soil properties were influenced by plant community more than by boar rooting disturbance. Lastly, I found that rooting disturbance rather than seed dispersal by wild boar facilitates further invasion by plants. Overall, these findings indicate that wild boar can have profound impacts on native ecosystems.