Reconstructing Megafauna-Vegetation Interaction Across Spatial and Temporal Scales

Megafauna is a driver of ecosystem processes, and influences nutrient cycling, vegetation dynamics, and biodiversity. This dissertation explores the complex interactions between megafauna and vegetation across temporal and spatial scales, offering insights into past ecosystems and their implications for contemporary conservation. Chapter 1 provides a comprehensive review of paleodietary reconstruction methods, integrating diverse proxies to reconstruct past trophic interactions. Chapter 2 focuses on the dietary ecology of Mammuthus primigenius, analyzing 50 coprolites from Siberia to evaluate their keystone role in the mammoth steppe biome. Chapter 3 explores a sedimentary ancient DNA record from Andy Lake (Alaska) to investigate the effects of herbivory on plant diversity. Chapter 4 uses satellite imagery to quantify vegetation productivity changes across three rewilding experiments, highlighting the ecological impacts of modern large herbivore reintroductions. Together, these studies reconstruct present and past interactions between megafauna and vegetation to inform strategies for biodiversity restoration and climate resilience.