Wild Ungulate Herbivory of Willow on Two National Forest Allotments in Wyoming

Abstract

Abstract Willows (Salix) are important riparian plants and often used to indicate riparian condition. Many herbivores feed on willows, but there is limited information about willow browsing by wildlife except in national parks. This study was conducted to estimate wild ungulate herbivory of willow on two US Forest Service allotments in northern Wyoming and to compare these values to published estimates for national parks. We also compared total annual and seasonal willow utilization by wildlife between sites dominated by willows of different heights. The effects of height category, site, and season on willow utilization were determined with a repeated measures analysis. Four permanent willow utilization transects were established at each of six study sites per allotment on two allotments, in communities supporting planeleaf (Salix planifolia Pursh), Wolf's (Salix wolfii Bebb), Drummond's (Salix drummondiana Barratt ex Hook.), or Eastwood's (Salix eastwoodiae Cock. ex A. Heller) willow. Twenty-five twigs w...