Howling About Trophic Cascades

Abstract

AbstractFollowing evolutionary theory and an agriculture model, ecosystem research has stressed bottom-up dynamics, implying that top wild predators are epiphenomenal effects of more basic causes. As such, they are assumed expendable. A more modern co-evolutionary and wilderness approach — trophic cascades — instead suggests that top predators, whose effects flow down to fundamental biological processes, are co-equal causes of ecosystem health. Their survival, then, should be supported. This article, based on extensive research including the author's participation in a major field project, provides informational resources for teaching trophic cascades, using wolves as a case study. As charismatic, iconic, thriving but still endangered, well-studied, and terrestrial carnivores, wolves are ideal for enlightening students about what otherwise might be dry abstractions about crucial ecosystem processes. The article ends with student exercises and broader lessons for environmental education.