To educate a man in mind and not in morals is to educate a menace to society. -Theodore Roosevelt

B&C Fellow - Cristina Eisenberg


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.


Cristina Eisenberg
Oregon State University


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"The wildlife and its habitat cannot speak. So we must and we will."

-Theodore Roosevelt