Available online 31 May 2016
Original Research
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- a Rangeland Scientists, US Department of Agriculture − Agricultural Research Service, Eastern Oregon Agricultural Research Center, Burns, OR 97720, USA
- b Assistant Professor, Department of Forest, Rangeland, and Fire Sciences, University of Idaho, Moscow, ID, 83844, –1142, USA
- c Professor Emeritus, Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR 97331, USA
- d Professor, Plant & Wildlife Sciences, Brigham Young University, Provo, UT 84601, USA
- Received 1 January 2016, Revised 14 March 2016, Accepted 25 April 2016, Available online 31 May 2016
Abstract
Juniper
and piñon coniferous woodlands have increased 2- to 10-fold in nine
ecoregions spanning the Intermountain Region of the western United
States. Control of piñon-juniper woodlands by mechanical treatments and
prescribed fire are commonly applied to recover sagebrush steppe
rangelands. Recently, the Sage Grouse Initiative has made conifer
removal a major part of its program to reestablish sagebrush habitat for
sage grouse (Centrocercus urophasianus) and other species. We
analyzed data sets from previous and ongoing studies across the Great
Basin characterizing cover response of perennial and annual forbs that
are consumed by sage grouse to mechanical, prescribed fire, and
low-disturbance fuel reduction treatments. There were 11 sites in
western juniper (Juniperus occidentalis Hook.) woodlands, 3 sites in singleleaf piñon (Pinus monophylla Torr. & Frém.) and Utah juniper (Juniperus osteosperma [Torr.] Little), 2 sites in Utah juniper, and 2 sites in Utah juniper and Colorado piñon (Pinus edulis Engelm). Western juniper sites were located in mountain big sagebrush (A. tridentata ssp. vaseyana) steppe associations, and the other woodlands were located in Wyoming big sagebrush (A. tridentata ssp. wyomingensis)
associations. Site potential appears to be a major determinant for
increasing perennial forbs consumed by sage grouse following conifer
control. The cover response of perennial forbs, whether increasing (1.5-
to 6-fold) or exhibiting no change, was similar regardless of conifer
treatment. Annual forbs favored by sage grouse benefitted most from
prescribed fire treatments with smaller increases following mechanical
and fuel reduction treatments. Though forb abundance may not
consistently be enhanced, mechanical and fuel reduction conifer
treatments remain good preventative measures, especially in phase 1 and 2
woodlands, which, at minimum, maintain forbs on the landscape. In
addition, these two conifer control measures, in the short term, are
superior to prescribed fire for maintaining the essential habitat
characteristics of sagebrush steppe for sage grouse.
Key Words
- conifer woodland;
- fuel reduction;
- juniper;
- prescribed fire;
- sagebrush
Published by Elsevier Inc. on behalf of The Society for Range Management.
