2025/07/27 by Daniel R. MacNulty, David Cooper, Michael Procko +1 · 1 voice
Environmental Science · Agricultural and Biological Sciences · Health Professions · #Wildlife Ecology and Conservation #Forest Ecology and Biodiversity Studies #Indigenous Studies and Ecology
paper · pdf · doi:10.32942/x2qq0c
Ripple et al. (2025) recently argued that large carnivore recovery in Yellowstone National Park triggered one of the world’s strongest trophic cascades, citing a ~1500% increase in willow crown volume derived from plant height data. In this comment, we show that their conclusion is invalid due to fundamental methodological flaws. These include use of a tautological volume model, violations of key modeling assumptions, comparisons across unmatched plots, and the misapplication of equilibrium-based metrics in a non-equilibrium system. Additionally, Ripple et al. rely on selectively framed photographic evidence and omit critical drivers such as human hunting in their causal attribution. These shortcomings explain the apparent conflict with Hobbs et al. (2024), who found evidence for a relatively weak trophic cascade based on the same height data and a long-term factorial field experiment. Our critique underscores the importance of analytical rigor and ecological context for understanding trophic cascade strength in complex ecosystems like Yellowstone.