Use of Felled Junipers to Protect Streamside Willows From Browsing

Abstract

Willow (Salix) communities are important components of riparian ecosystems. However, browsing by livestock and wildlife species can negatively impact willow size and abundance, and make restoration efforts difficult. A common solution has been fencing of affected willows to exclude ungulates, but fencing is expensive and may not complement desirable land management strategies. An alternative to fencing is the use of structures that limit access to streamside willows, without excluding ungulate access to the entire riparian zone. We examined the use of felled western juniper trees (Juniperus occidentalis Hook) placed over streamside willow shrubs. Four replicates of felled western juniper treatments (covered) and noncovered treatments were applied to a 1.2-km length of stream in southeastern Oregon. Willows (< 2 m) within treatment areas were censused, tagged, examined for evidence of browse-use, and measured for maximum height during August 2002, before treatment. Posttreatment measurements were made in August and October 2003. Results indicate that by August 2003 (posttreatment) the average growth of willows in covered treatments was 25 cm (480%) greater than in noncovered treatments. By October 2003 (posttreatment), more shrubs were browsed in noncovered (84%) than covered (39%) treatments. Our data suggest that covering small willow shrubs (< 2 m tall) with felled western juniper is an effective deterrent to browsing.