The term “trophic cascade” refers to changes in a food web where energy is passed from one organism to others in that community. Famous wildlife ecologist Aldo Leopold first noted early in the 19th century that predators maintain a balance within an ecosystem.
Trophic cascades are powerful indirect interactions that can control entire ecosystems. Trophic cascades occur when predators limit the density and/or behavior of their prey and thereby enhance survival of the next lower trophic level.