Chapter 23 The Madison Headwaters Elk Herd: Transitioning from Bottom–Up Regulation to Top–Down Limitation

摘要: Theme Predator–prey dynamics encompass an intriguing body of ecological processes that is embedded in all biological communities because virtually every organism predator, prey, or both. The influence predators on their prey populations active area research, with the “bottom–up” perspective suggesting are controlled by flowing from bottom food web up trophic chain. “top–down” suggests structure controlling abundance and distribution consequences cascading down Understanding concurrent, relative influences bottom–up top–down wolf–ungulate systems important for effective management conservation these large mammal diversity landscapes where they exist being restored. However, insights into underlying most have typically been confounded human harvests ungulates, wolves, historic debate concerning ungulate overabundance Yellowstone National Park recent reintroduction wolves system ∼70 years after extirpation provided opportunity to evaluate potential communities. Madison headwaters elk herd remains within park not subjected harvest. Demographic studies prior wolf restoration clearly indicated this population was limited strongly regulated ( Chapter 11 Garrott et al. , volume). In chapter, we describe changes vital rates as recolonized eventually completely reoccupied study system.