Lack of evidence of significant impact of European rabbits on Patagonian forest regeneration

Abstract

The European rabbit (Oryctolagus cuniculus) is among the 100 most harmful invasive alien organisms worldwide designated by the International Union for Conservation of Nature. Therefore, the Argentine government officially declared this species as being detrimental to biodiversity conservation. Rabbits represent a potential threat to the regeneration of Patagonian forests, which host unique biodiversity and functional relationships. However, two local studies that evaluated diet composition using microhistological analysis of feces in the north and south of Patagonian forests found that trees represent a small proportion of the annual diet of rabbits. The objective of this study was to evaluate the impact of rabbits on saplings in an area of Patagonian forest with high rabbit densities. We sampled 294 saplings for rabbit herbivory in 20 1-ha forest plots adjacent to grasslands and shrublands in Lanin National Park, Argentina. No evidence of tree regeneration limitations was found in the affected stands, which concurs with the results of previous local studies on diet composition. Other anthropogenic impacts, such as domestic ungulate breeding, intentional fires, urban growth, and forestry, appear to represent more serious threats to Patagonian forests than rabbit herbivory.