Abstract
The conservation management of elephant focuses on identifying and mitigating the extent and intensity of their effects on biodiversity. However, variation in the intensity of the effects between elements of biodiversity is seldom explored, which limits our ability to interpret the scale of the impacts. Our study quantifies >50 years of elephant effects on the canopy shrubs (a key functional guild) of the Addo Elephant National Park, assessing the impacts across a spectrum of structural components in the community, ranging from the composition and structure of the community to the structure of individual canopy species. We show the vulnerability of succulent thicket to transformation as the accumulated influences of elephant alter community composition and structure, and consequently ecological functioning. The pattern of transformation is similar to that caused by domestic herbivores, which leads us to predict that elephant will eventually bring about landscape-level degradation and a significant loss of biodiversity. While we expected the influences on the canopy species to provide insight into the responses of the community as a whole, we demonstrate an uneven distribution of impacts between constituent elements. This implies that the canopy dominants might not be useful indicators of community change in thicket, a pattern that is likely reflected among the canopy trees of savanna systems. Our findings have important implications for monitoring, and suggest that predicting elephant impacts across habitats requires a broader and more integrated understanding of the mechanisms driving the changes between elements of biodiversity at various spatial and temporal scales.