CORVALLIS, Ore. Sufficient advances have been made about the importance of top predators in ecosystem function that it's time to move from discussing the issue to acting upon it, a conservation biologist from Oregon State University suggests in a new book.
In "The Wolf's Tooth: Trophic Cascades, Keystone Predators and Biodiversity," just published by Island Press, Cristina Eisenberg outlines the many research findings in recent decades about "trophic cascades," or the string of problems that can be created when keystone predators ranging from wolves to sharks or even spiders are removed from an ecosystem, allowing other species to disproportionately flourish and cause havoc.
In particular, Eisenberg said, more has been learned about the significance of top predators on terrestrial systems, since their role in marine ecosystems was already more advanced. Scientists have now come to understand how wolves, cougars, bears and other leading carnivorous predators, which humans largely eliminated by the early 20th century, served a critical role in ecosystem function.
"The ecological concept of the 1990s was biodiversity, and that's important," said Eisenberg, who is the Boone and Crockett Fellow and a doctoral student in the OSU College of Forestry. "But in the next generation we want the concept of trophic cascades to have that same general awareness, because it's important too and essential to maintaining biodiversity. And we already know enough that it's time to start using these concepts to help ecosystems recover, not just in national parks or wilderness areas but everywhere."
These concepts have gained the most public awareness, Eisenberg said, with the return of wolves to Yellowstone National Park. Wolves have helped to control the overgrazing done by elk, both by reducing their populations and also changing their behavior in what has been identified as "the ecology of fear." As a result, young aspen and willows are be
|Contact: Cristina Eisenberg|
Oregon State University