Douglas-fir's effect on mountain big sagebrush wildlife habitats

• Published in: Wildlife Society bulletin 2005-04, Vol.33 (1), p.74-80
• Main Authors: Grove, Adam J., Wambolt, Carl L., Frisina, Michael R.
• Format: Article
• Language: English
• Subjects: Artemisia tridentata; Artemisia tridentata vaseyana; canopy; canopy cover; conifer establishment; Conifers; Douglas-fir; DOUGLAS-FIR AND SAGEBRUSH; Effects; Forage; Forest canopy; Habitat Management; Habitats; Mammals; Modeling; mountain big sagebrush; Musical intervals; Pseudotsuga menziesii; Regression analysis; Trees; understory; Wildlife; Wildlife conservation; wildlife habitat; Wildlife habitats; Wildlife management
• ISSN: 0091-7648; 1938-5463
• DOI: 10.2193/0091-7648(2005)33[74:DEOMBS]2.0.CO;2

Control of establishing conifers to lessen their impacts on understory is a contentious habitat issue throughout the western United States. Our objective was to model the effect of increasing Douglas-fir (Pseudotsuga menziesii) canopy cover on mountain big sagebrush (Artemisia tridentata vaseyana) canopy cover. We sampled 25 sites, representing different levels of Douglas-fir establishment, within each of 3 southwestern Montana mountain big sagebrush communities. Over all sites, Douglas-fir canopy cover had a significant correlation (r = −0.86; P < 0.001) to mountain big sagebrush canopy cover. Regression models were variable among study areas as linear and curve-linear declines in mountain big sagebrush canopy cover were found. While model validation results indicated that individual study-area models were marginal for predicting relationships for the other study areas, the overall model developed from all sites combined generally predicted individual sites well, especially when mountain big sagebrush cover was 20% to