Effect of large and small herbivores on seed and seedling survival of Beilschmiedia miersii in central Chile

Abstract

In the Mediterranean region of Chile, populations of the threatened tree Beilschmiedia miersii have been strongly affected by anthropic disturbances, causing a critical state of conservation. Herbivory has been proposed as the main factor that currently limits the regeneration of this species. We studied the effect of large vs. small herbivores on seed and seedling survival of B. miersii under two contrasting habitat conditions (forest and shrubland), using plots with fenced enclosures which differentially excluded mammalian herbivores according to body size. Results show that herbivory had a significant negative effect on B. miersii. Both large and small herbivores had a significant negative effect on seeds and seedlings in the shrub habitat. In the forest habitat small herbivores had a significant negative effect only on seeds. Our results suggest that different herbivores can have varying effects on seed and seedling survival, but these effects can vary spatially, probably due to different herbivore assemblage of each habitat. Results suggest that restoration plans for B. miersii need to be adjusted according to local conditions.