Context-dependent effects of shifting large herbivore assemblages on plant structure and diversity

Despite wide recognition of the importance of anthropogenically driven changes in large herbivore communities – including both declines in wildlife and increases in livestock – there remain large gaps in our knowledge about the impacts of these changes on plant communities, particularly when combined with concurrent changes in climate. Considering these prominent forms of global change in tandem enables us to better understand controls on savanna vegetation structure and diversity under real-world conditions.We conducted a field experiment using complete and semi-permeable herbivore exclosures to explore the difference in plant communities among sites with wild herbivores only, with cattle in addition to wild herbivores, and with no large herbivores. To understand variation in effects across climatic contexts, the experiment was replicated at three locations along a topoclimate gradient in California. Critically, this is the first such experiment to compare cattle and wildlife impacts a...