Study
Are wolves saving Yellowstone’s aspen? A landscape-level test of a behaviorally mediated trophic cascade
Kauffman, Matthew J.; Brodie, Jedediah F.; Jules, Erik S.
Ecology, 2010
Aspen stands across northern Yellowstone were sampled along a measured gradient of wolf predation risk, testing the specific prediction that aspen should recover where elk are most afraid to browse.
- Studied in
- Canis lupus, Cervus canadensis, Populus tremuloides
- Sample size
- aspen stands sampled across a gradient of wolf predation risk
Aspen were not recovering preferentially in high-risk areas. Browsing intensity did not track predation risk in the way the behaviourally mediated cascade predicts, and no landscape-wide aspen recovery was detected.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
The behaviourally mediated trophic cascade in Yellowstone aspen is not supported at landscape scale.
How NatureHQ reads it
NatureHQ holds this paper alongside the cascade literature deliberately rather than choosing between them. The disagreement is genuine and unresolved, and it is a good example of why an evidence status of "contested" is a real answer rather than a failure to reach one. Note also what is being tested: not whether wolves affect elk, which is not in doubt, but whether fear of wolves redistributed browsing enough to regrow a forest.
- Aspen only; willow and cottonwood show different and sometimes stronger responses.
- Predation risk is estimated from wolf use and terrain rather than measured directly on individual elk.
- A snapshot fifteen years in; slow vegetation responses could still be under way.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Wiley journalsPublished in a Wiley journal.
This reference was resolved automatically against Crossref on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-09.