The effect of introduced herbivores upon an endangered tree (Beilschmiedia miersii, Lauraceae)

Beilschmiedia miersii is an endemic endangered tree of central Chile, protected only in La Campana National park. The regeneration of B. miersii is very low, presumably due to strong fruit and seedling predation by livestock. The aim of this study was to establish whether herbivores impact recruitment in populations of the species. In particular, we want to compare the herbivore effect in non-protected populations with protected populations inside a national park. We compared demographic features and the regeneration process in four populations, two located inside and two outside the park. We expect populations inside the park to exhibit a significantly greater recruitment, expressed in seedling establishment and survival, relative to those outside the park. Outside the park, livestock predation on fruits and herbivory on seedlings could hamper recruitment. However, fruit and seedling predation was similarly high both inside and outside the park, posing a significant constraint on the regeneration of B. miersii. The main associated causes were the presence of livestock and seedling desiccation. If the survival of B. miersii is to be achieved, managing livestock pressure, possibly through zoning, seems mandatory.