ARS | Publication request: GREAT BASIN REDBAND TROUT HABITAT IMPROVEMENT USING FELLED WESTERN JUNIPER

Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 2, 2003
Publication Date: February 6, 2003
Citation: MATNEY, C.A., STRINGHAM, T.K., BOYD, C.S. GREAT BASIN REDBAND TROUT HABITAT IMPROVEMENT USING FELLED WESTERN JUNIPER. SOCIETY FOR RANGE MANAGEMENT MEETING ABSTRACTS. 2003. V. 56. PAPER NO. 156.

Interpretive Summary: Stream habitats for Great Basin redband trout have been altered by land management practices, and their streamside riparian shrubs and cover have been reduced. Stream water temperatures have been affected, with summer temperatures reaching levels lethal to redband trout. The objectives of this study are to determine if placement of felled Western juniper over a stream channel 1.) moderates maximum summer stream temperatures, 2) is an effective protective structure for reducing ungulate herbivory, and 3) affects movement of redband trout. The study area is located approximately 100 km South of Burns, Oregon. The reach was divided into 8 blocks of equal length: 500 feet (152.4 m). Blocks were alternated covered-open. One hundred redband trout were tagged with Passive Integrated Transponders (PIT) tags during June 20-30 and were monitored for movement from July through October by swim-through PIT tag antennae located at block intersections. Water thermistors were located within each block as well as locations above and below the study blocks. Point-in-time stream flow measurements were taken approximately every 10 days. Willow shrubs were censused and measured for volume and distance from stream water's edge during August. Juniper trees were placed over the stream from September 1-10. Covered blocks received approximately 30% cover. Pre-treatment data was collected in summer of 2002, and post-treatment data will be collected during summer 2003.

Technical Abstract: Great Basin redband trout (Oncorhynchus mykiss newberri) often exist in streams listed by the Oregon Department of Environmental Quality as water quality limited due to stream water temperature. Efforts to manage stream temperature have focused on maintenance or improvement of streamside vegetation through riparian fencing and vegetation planting projects. However, in remote locations these options are often not viable. Our study is investigating the use of felled Western juniper (Juniperus occidentalis), placed over the stream channel, as an alternative to fencing. The objectives of our study are to 1) determine if Western juniper cover moderates summer stream temperatures 2) determine if Western juniper placed over streamside willow shoots is an effective protective structure for reducing ungulate herbivory, and 3) describe the movement and distribution of native redband trout in relation to placement of Western juniper over the stream channel. The study area is located on the headwaters of a Steens Mountain stream, approximately 100 km south of Burns, Oregon. The stream reach was divided into 8 blocks of 152.4 m each. Blocks were alternated covered-open. One hundred redband trout were tagged with Passive Integrated Transponders (PIT) tags during June 2002 and were monitored for movement from July through October by PIT tag antennae located at block intersections. Water temperature, point-in-time discharge, and willow (Salix spp.) volume and location were recorded within each block. Juniper trees were placed over the stream in September 2002, and low-level aerial photos were taken for cover calculation. Project methodology and instrumentation will be presented.