Hosted by SER's Midwest Great Lakes Chapter, this presentation reviews primary ecological principles to illuminate the importance of disturbance ecology as the primary renewal mechanism in ecosystems. This presentation defines disturbance and identifies the top-level disturbances, herbivory and fire, associated with natural areas prior to settlement. Keystone herbivores are highlighted and modeled for structural impacts and nutrient cycling that benefited highly evolved, graze-fire obligate biological assemblages. The presentation then models the impacts and biotic / abiotic trajectories associated with the removal of keystone processes. Presentation ends by modeling and providing case studies for how to restore herbivory and fire in ways that mimic historic patterns and processes.