|Matney, Casey - OREGON STATE UNIV|
|Stringham, Tamzen - OREGON STATE UNIV|
Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 10, 2004
Publication Date: November 1, 2005
Citation: Matney, C.A., Boyd, C.S., Stringham, T.K. 2005. Use of felled junipers to protect streamside willows from browsing. Rangeland Ecology and Management. 58:652-655. Interpretive Summary: Herbivory by wild and domestic ungulates may limit growth and reproduction of streamside willow plants, reducing stream shading, and increasing the chances for summertime stream temperature extremes. Our objective was to determine if felled western juniper trees placed over small (<2m tall) willow shrubs could be used as an effective protective structure for reducing the impacts of ungulate browsing. Our results indicate that covering of willows more than tripled interannual growth and decreased incidence of browsing by approximately 50%. This work provides managers with an effective restoration tool that reduces herbivory and increases growth of streamside willow shrubs.
Technical 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 this procedure 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 application of felled western juniper trees placed over streamside willow shrubs. Four 152m-feleed western juniper treatments of covered and non-covered were applied to a 1.2km length of stream in southeastern Oregon. Willows (<2m) within treatment areas were censused, tagged, examined for evidence of browse-use, and measured for maximum height during August 2002, prior to treatment. Measurements were repeated August 2003 and October 2003 after treatment. Results indicate that by August 2003 (post-treatment) growth of willows in covered treatments was 25cm greater than that of willows in open treatments (P=0.02), and by October 2003 (post-treatment), more shrubs were browsed in open (84%) compared to covered (38%) treatments (P=0.002). Our data suggest that covering small willow shrubs (<2m tall) with felled western juniper is an effective deterrent to browsing.