Trophic cascades and dingoes in Australia: Does the Yellowstone wolf–elk–willow model apply?

Abstract

Wolves are widely regarded as top-down regulators of prey and trophic cascades in North America. Consequent expectations of biodiversity benefits from canid-driven trophic cascades have driven debate around reintroduction plans for dingoes in south-eastern Australia. The biophysical characteristics of Yellowstone National park predispose that environment to trophic cascades but it is not clear that Australia provides a comparative context for dingoes. The wolf-elk-willow trophic cascade in Yellowstone National Park provides a key case study for understanding the broader system controls on trophic interactions. Here, we compare similarities and dissimilarities of the Yellowstone National Park model and the south-eastern Australian environments where dingo reintroductions have been proposed. Both systems feature a canid top predator in an arid environment, so their superficial comparison is seemingly relevant for dingo reintroduction plans. Climate stability however, critically underpins Yellowstone's trophic cascades with regular and predictable resource supply sustaining the strong trophic interactions there. In contrast, the renowned instability of the climate of inland Australia makes resource availability relatively unpredictable. This fundamental difference means that south-eastern Australia is unlikely to sustain trophic interactions of similar strength to those in Yellowstone.