A recent peer-reviewed analysis has challenged claims that wolf recovery in Yellowstone National Park triggered a dramatic ecosystem-wide change. Researchers argue that a 2025 study overstated the effects on willow growth due to flawed methods.
The analysis, published in Global Ecology and Conservation, reexamined data from earlier research and found no support for a park-wide surge in willow growth after wolves returned.
Lead author Dr. Daniel MacNulty of Utah State University said the original conclusions relied on circular reasoning in statistical models that used plant height both to calculate and predict willow volume.
Co-author Dr. David Cooper of Colorado State University noted that effects appear modest and vary by location, influenced by factors like hydrology and browsing.
The new work contrasts with the 2025 study by Ripple et al. and aligns more closely with findings from Hobbs et al. in 2024 that reported only weak trophic cascade effects.
