Novel trophic cascades: apex predators enable coexistence

Arian D Wallach; William J Ripple; Scott P Carroll

doi:10.1016/j.tree.2015.01.003

Novel trophic cascades: apex predators enable coexistence

Trends Ecol Evol. 2015 Mar;30(3):146-53. doi: 10.1016/j.tree.2015.01.003. Epub 2015 Feb 13.

Authors

Arian D Wallach¹, William J Ripple², Scott P Carroll³

Affiliations

¹ Charles Darwin University, School of Environment, Darwin, Northern Territory, Australia. Electronic address: arian.wallach@cdu.edu.au.
² Trophic Cascades Program, Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA.
³ Institute for Contemporary Evolution, Davis, CA 95616, USA; Department of Entomology and Nematology, University of California, Davis, CA 95616, USA.

PMID: 25687158
DOI: 10.1016/j.tree.2015.01.003

Abstract

Novel assemblages of native and introduced species characterize a growing proportion of ecosystems worldwide. Some introduced species have contributed to extinctions, even extinction waves, spurring widespread efforts to eradicate or control them. We propose that trophic cascade theory offers insights into why introduced species sometimes become harmful, but in other cases stably coexist with natives and offer net benefits. Large predators commonly limit populations of potentially irruptive prey and mesopredators, both native and introduced. This top-down force influences a wide range of ecosystem processes that often enhance biodiversity. We argue that many species, regardless of their origin or priors, are allies for the retention and restoration of biodiversity in top-down regulated ecosystems.

Keywords: apex predator; invasive species; top-down regulation.

MeSH terms

Animals
Biodiversity*
Conservation of Natural Resources / methods*
Ecosystem
Food Chain
Introduced Species*
Population Dynamics
Predatory Behavior*