Abstract

Populations of beaver and willow have not thrived in riparian environments that are heavily 1 browsed by livestock or ungulates, such as elk. The interaction of beaver and elk herbivory may be an 2 important mechanism underlying beaver and willow declines in this competitive environment. We 3 conducted a field experiment that compared the standing crop of willow 3 years after simulated 4 beaver cutting on paired plants with and without intense elk browsing (~85% utilization rate). 5 Simulated beaver cutting with intense elk browsing produced willow that was small (biomass and 6 diameter) and short with far fewer but longer shoots and a high percentage of dead biomass. In 7 contrast, simulated beaver cutting without elk browsing produced willow that was large, tall, and 8 leafy with many more but shorter shoots (highly branched) and a low percentage of dead biomass. 9