REVERBERATING RESPONSES TO TROPHIC CASCADES ACROSS ECOSYSTEMS
The loss of apex predators is a worldwide phenomenon, and understanding the extent of direct and indirect effects of these losses or the potential responses to restoration of such predators is a fundamental challenge in ecology. We address this challenge in Yellowstone National Park (YNP) where the reintroduction of gray wolves has been hypothesized to initiate a terrestrial trophic cascade resulting in the patchy regeneration of riparian woody vegetation (RWV). RWV is known to influence stream-riparian linkages through changes in stream autochthonous and allochthonous resources. Moreover, insect emergence can be mediated by stream basal resources and fish predation, which ultimately can influence the abundance of riparian insectivores. We began investigating these potential reverberating responses to a terrestrial trophic cascade in YNP in 2018. At each site, we measured fish populations, stream invertebrates, and riparian spiders. Sites with reduced browsing, where top down control was initiated by wolves, tended to have higher stream invertebrate biomass, higher fish biomass, and higher abundances of riparian spiders. These results indicate that the top down control initiated by wolves may influence insect emergence flux and riparian insectivore responses.
Colden Baxter (Co-Presenter/Co-Author), Idaho State University, firstname.lastname@example.org;
Dana Warren (Co-Presenter/Co-Author), Oregon State University, email@example.com;
William Ripple (Co-Presenter/Co-Author), Oregon State University, firstname.lastname@example.org;
Jeremy Brooks (Primary Presenter/Author), Idaho State University, email@example.com;