Exclosures and artificial beaver dams were used to determine the cause of willow (Salix spp.) declines in Rocky Mountain National Park, Colorado. Elk (Cervus elaphus) herbivory reduced annual growth, height and number of catkins produced by willows, and reduced production of litter and herbaceous understory plants. Sites with artificial dams and increased water tables produced more herbaceous vegetation, but did not have greater willow production. The results of the study suggest that willows are most limited by elk grazing and that reducing elk populations or fencing them from riparian areas may enhance willow production. Reintroducing beaver to increase the height of the water table, planting willows and clipping willows to produce suckers, may also increase willow populations following reductions in grazing pressure.
Citations and enhanced abstracts for journals articles and documents focused on rangeland ecology and management. RSIS is a collaboration between Montana State University, University of Idaho, and University of Wyoming.