Michael R. Frisina

Effect of Method, Site, and Taxon on Line-Intercept Estimates of Sagebrush Cover

Abstract Sage-grouse (Centrocercus spp.) are arguably the best known of the many wildlife species that inhabit sagebrush (Artemisia spp.) ecosystems. Lack of standardization in the procedures used to assess sagebrush cover may contribute to inconsistencies in reported habitat requirements for sage-grouse and other wildlife. We compared 3 applications of the line-intercept method for 3 sagebrush taxa. We sampled 2 mountain big sagebrush (A. tridentata vaseyana) sites, 2 Wyoming big sagebrush (A. t. wyomingensis) sites, and 1 black sagebrush (A. nova) site to determine whether the results generated by the 3 methods differed. Percent cover as determined by agency methods was up to 2.6 times greater than that from research applications. Cover differences among techniques were influenced by taxa and site (P ≤ 0.001) because both affected shrub morphology. We believe it will be difficult to identify and achieve wildlife habitat guidelines for minimal sagebrush cover requirements if methodologies are not standardized.

Livestock Grazing, Wildlife Habitat, and Rangeland Values

livestock and wildlife values should be placed within this broader context. Ranchers and conservationists in the West realize that debates over grazing systems and stocking rates are of little consequence if rangelands continue to be lost or fragmented due to subdivision, farming, weed invasion, catastrophic wildfi re, and energy development. However, impacts of domestic grazing that diminish land value via reduced range productivity and wildlife habitat quality can also lead to alternative land uses and habitat conversion. Maintaining the multiple values of western rangelands will require a shift from local to landscape conservation to match the scale of land use change that threatens grazing, rural ways of life, and wildlife habitat. The future of western rangelands is in developing partnerships that help keep sustainable grazing the prevailing land use. Indeed, as rangelands are lost to other land uses, overlapping interests will make conservation partners out of otherwise odd associates—ranchers need open space for grazing and wildlife biologists, managers, and other conservationists want to maintain or enhance the wildlife values on working ranches. In this paper, we review a representative sampling of scientifi c literature to document grazing impacts on wildlife and its habitat to better understand the roles of grazing strategies in wildlife habitat conservation. Further, we explore commonalities between grazing and conservation interests and provide a vision for advancing wildlife and habitat management and conservation.

A method for determining the onset year of intense browsing.

A survey based on browsing related architectures indicated that browsing level had increased at the Mt. Haggin Wildlife Management Area. We describe a technique for determining the year in which the increase in browsing level occurred. The technique is based on the analysis of stems old enough to have experienced the early period of light browsing; the onset year of intense browsing was determined by using dendrochronology to date the formation of twig clusters produced by intense browsing. Stems from 20 Geyer willow (Salix geyeriana Anderss.) plants were analyzed from each of 6 study sites. Mean onset years at the 6 sites ranged from 1983.1 to 1988.4; the mean onset year for all 6 sites was 1985.4 +/- 0.5 SE (N = 120). The reconstructed history was used to evaluate the relationship between moose (Alces alces) number and browse trend. From 1976 to 2000, the winter trend census of moose increased from 7 to 56. The onset of intense browsing in 1985 occurred when 23 moose were counted. DOI:10.2458/azu_jrm_v56i1_keigley

Grazing effects on nutritional quality of bluebunch wheat-grass for elk.

We tested the hypothesis that nutrient content of bluebunch wheatgrass (Agropyron spicatum [Pursh] Scribn. &Smith) either cattle grazed in the spring, rested from cattle grazing for a full year, or given long term rest would all be equal during the given season at 1 location. A 3 pasture rest-rotation grazing system and an exclosure on the Mt. Fleece elk winter range in southwestern Montana were studied during 4 seasons over 3 years. Only nitrogen (N) and phosphorus contents were generally greater in the in the spring grazed regrowth pasture. However, regrowth from bluebunch wheatgrass grazed in the spring did not improve the species nutrient content for wildlife the following winter over nongrazed treatments. During winter when elk (Cervus elaphus nelsoni Bailey) are present, N, TDN, and IVDMD were not among the 3 treatments. Elk were determined unlikely to consume enough bluebunch wheatgrass to meet protein maintenance requirements during winter. Our findings resulted from analyses repeated over the 3 years for a complete cycle of a 3 pasture rest-rotation system: however, our hypothesis needs to be tested at other locations before assuming the same results elsewhere.

Aspen Height, Stem-girth and Survivorship in an Area of High Ungulate Use

An increase in ungulate population size potentially exposes aspen suckers, saplings, and trees to increased use. This study examined how stem height and girth influenced the selection of stems by ungulates for browsing, rubbing, and gnawing, and reconstructed the history of ungulate use for the study area. Transects were run through each of three aspen clones growing in southwestern Montana to determine height, circumference, and the surface area from which bark was totally and partially removed by rubbing and gnawing. Stems 20–250 cm tall were browsed. Stems 2–13 cm diameter were preferentially selected for rubbing and gnawing. The area of totally removed bark on dead saplings was twice the area of removed bark on live stems of similar diameter, suggesting that bark removal played a major role in the death of some stems. Based on an analysis of stem height and age, ungulate browsing was inferred to have increased from a light-to-moderate level to an intense level in 1991. The depth of scars was used to date scarring events. An increase in rubbing and gnawing was determined to have occurred about 1985. We concluded that elk were primarily responsible for the observed impacts. The combined effect of rubbing, gnawing, and browsing affects a broader span of ages compared to the effect of browsing alone. If prescribed fire is used to rejuvenate aspen stands, the resulting young stems should be protected from heavy browsing, rubbing and gnawing until they reach about 13 cm diameter and have grown out of the browse zone.

Society for Range Management Issue Paper: Ecology and Management of Sage-Grouse and Sage-Grouse Habitat—A Reply

Society for Range Management issue paper: ecology and management of sage-grouse and sage-grouse habitat--a reply. DOI:10.2458/azu_rangelands_v28i3_Schroeder

Keying In On Big Sagebrush

A guide for identifying the four subspecies of big sagebrush DOI:10.2458/azu_rangelands_v26i1_frisina

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

Abstract 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 <15%. Mountain big sagebrush canopy cover declined from >20% to <15% and <5% as Douglas-fir canopy cover increased beyond 20% and 35%, respectively. At least 92 species of mammals and 93 species of birds having either an obligatory or a facultative relationship with sagebrush are affected to differing degrees by loss of sagebrush cover.

Characteristics of shrub morphology on nest site selection of Greater Sage-Grouse (Centrocercus urophasianus) in high-elevation sagebrush habitat

ABSTRACT Selection of nest sites directly influences reproductive success for Greater Sage-Grouse (Centrocercus urophasianus); thus, regional evaluation of how this species selects nest sites is necessary for effective habitat management. We evaluated fine-scale nest site selection of Greater Sage-Grouse in the Centennial Valley of southwest Montana. We conducted vegetation surveys at nest sites (n = 90) of radio-tagged Greater Sage-Grouse and paired random locations across 2 breeding seasons (2014–2015). The majority of nests were located under mountain big sagebrush (Artemisia tridentata ssp. vaseyana), three-tip sagebrush (A. tripartita), and basin big sagebrush (A. tridentata ssp. tridentata) shrubs. We used generalized linear models and information theory to evaluate competing hypotheses about nest site selection. Our top model indicated that nest site selection was primarily associated with nest shrub morphological characteristics and cover provided by the nest shrub. Mountain big sagebrush and three-tip sagebrush provided twice the amount of lateral cover that basin big sagebrush shrubs provided. Our results suggest that herbaceous cover was unimportant at fine scale nest site selection of Greater Sage-Grouse in our study area. Managers should focus on conserving large intact stands of mountain big sagebrush and three-tip sagebrush habitats because they provided the most lateral cover and supported the majority of nest sites.