Restoration ecology: are we forgetting top-down control?

Posted on June 1, 2016

Authors of a recent review article argue that restoration ecologists rely heavily on the assumption that natural communities are controlled by bottom-up processes (i.e., the upward transfer of nutrients and energy from plants to animals), but tend to ignore the complementary effects of top-down control by animals on nutrient cycling and the abundance and diversity of plants. They urge practitioners to try to re-establish both top-down and bottom-up controls by targeting the species composition of food webs more explicitly. They suggest that food web theory can be applied to restoration by methods such as: increasing variation in habitat types to foster trophic structure; increasing plant diversity and complexity to encourage total biodiversity and ecosystem stability; adding plant litter (e.g., by planting trees) to assist decomposition and nutrient cycling; introducing top predators to trigger trophic cascades; and removing non-native top predators, especially invasive species. As an aquatic example of the removal of non-native species, the authors cite the rapid recovery in the trophic position of a native apex predator (lake trout) following the elimination of a non-native apex predator (smallmouth bass).


Fraser, L.A. et al. 2015. A call for applying trophic structure in ecological restoration. Restoration Ecology 23(5), 503–507.

Lepak J.M. et al. 2006. Rapid food web recovery in response to removal of an introduced apex predator. Canadian Journal of Fisheries and Aquatic Sciences 63, 569–575.