B&C Fellow - Cristina Eisenberg

Oregon State University - PhD Graduated in 2012 -  B&C Professional Member
Food web relationships involving fire, wolves, elk, and forest ecosystems

In the rural west, geography defines us. I live on the shoulder of Red Owl Mountain, one of the many mountains that make up the Swan Range, which is part of the crazy quilt of mountain ranges that forms the Rocky Mountains in northwest Montana. My cabin lies at the north end of a shoestring valley located between the Swan Range and the Mission Mountains. The Swan River flows through this valley, with the Continental Divide a few miles east, as the eagle flies. The grizzly and wolf populations outnumbers the human population here, giving new meaning to coexistence and sustainability.

Inspired by living closely with large predators, I have been studying their conservation and ecology. For my MA in Environmental Studies, I studied wolf ecology and management, with a focus on the work of Aldo Leopold. For my PhD in Forestry and Wildlife, I am studying food web linkages and the factors that can shape plant communities and ecosystems. My research project is on trophic cascades involving humans, wolves, elk, and aspen in Glacier National Park in Montana and in Waterton Lakes National Park in Canada. I am also continuing to research Aldo Leopold's work in the realm of wildlife ecology.

Other interests include writing and teaching. I have a contract with Island Press and am writing a book, Landscapes of Hope: Trophic Cascades and Biodiversity, to be published in spring 2010. At Oregon State University's College of Forestry I co-teach two courses, Aldo Leopold and Ecosystem Management, with William J. Ripple, and The Role of Top Predators in Sustaining Forest and Riparian Ecosystems, with K. Norman Johnson.

TROPHIC CASCADES INVOLVING HUMANS, WOLVES, ELK, AND ASPEN IN THE CROWN OF THE CONTINENT ECOSYSTEM

Predation by wolves (Canis lupus) may be critical for maintaining biodiversity and sustaining aspen (Populus tremoloides) communities. Currently in decline throughout the West, aspen provides key habitat for songbirds and beaver (Castor canadensis), among other species. One of the major controversies in ecology in the past century concerns whether food has a stronger influence on herbivore population regulation than predation. Predation can drive strong lethal and non-lethal effects throughout food webs, referred to as trophic cascades. I am studying trophic cascades involving wolves, elk (Cervus elaphus), and aspen in the Crown of the Continent Ecosystem. I am investigating how an apex predator affects aspen communities by influencing abundance and behavior of large herbivore prey. This study is located in Glacier National Park, Montana and Waterton Lakes National Park, Alberta, in the Crown of the Continent Ecosystem, which spans the US/Canada border.

My research questions include: (1) Is high wolf abundance positively correlated with sustained aspen overstory recruitment? (2) Do wolf-driven trophic cascades include elk behavior effects due to predation risk? (3) Does plant and herbivore species diversity decrease as wolf abundance decreases?

This research is part of an interagency research project, The Southwest Alberta Montane Elk Study, which involves a collaboration between the University of Alberta, the University of Calgary, Oregon State University, Shell Canada, the Alberta Fish and Wildlife Division, Parks Canada, and the National Park Service. We are working with 100 GPS collared elk and several GPS collared wolf packs to evaluate elk and wolf resource selection and habitat needs.

As part of my PhD work, I am writing a book about trophic cascades to be published by Island Press in spring 2010: Landscapes of Hope: Trophic Cascades and Biodiversity.