The U.S. Geological Survey has provided full-text access to the following publication: Chapter 2: Sagebrush-associated species of conservation concern By Mary M. Rowland, Lowell H. Suring, Matthias Leu, Steven T. Knick, and Michael J. Wisdom Published in: Sagebrush ecosystem conservation and management: Ecoregional assessment tools and models for the Wyoming Basins, 2011, p. 46-68 Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. The U.S. Geological Survey has been given express permission by the publisher to provide full-text access online for this publication, and is posted with the express permission from the Publications Warehouse Guidance Subcommittee. Sagebrush Ecosystem Conservation and Management: 46–68, 2011 Chapter 2: Sagebrush-Associated Species of Conservation Concern Mary M. Rowland, Lowell H. Suring, Matthias Leu, Steven T. Knick, Michael J. Wisdom Abstract. Selection of species of con- Key words: ecoregional assessment, cern is a critical early step in conducting sagebrush ecosystem, species of conserva- broad-scale ecological assessments for tion concern, species selection, terrestrial conservation planning and management. vertebrates, vascular plants, Wyoming Ba- Many criteria can be used to guide this sins. selection, such as conservation status, ex- Ecoregional assessments may rely on isting knowledge base, and association coarse- or fine-filter approaches or both, with plant communities of interest. In depending on specific objectives of the conducting the Wyoming Basins Ecore- assessment. Coarse-filter approaches, gional Assessment (WBEA), we followed which are typically based on conserving a step-wise process to select vascular plant ecological communities, are often easier and vertebrate species of concern. Based to implement but may not capture occur- on our selection process, we identified 65 rences of rare or locally common species taxa of sagebrush-associated (Artemisia or other key habitat elements (Scott et al. spp.) vascular plants of conservation con- 1993, Noss and Cooperrider 1994, Haufler cern. The vast majority were forbs, and 1999b, Marcot and Flather 2007). More- nearly all are found in Wyoming (n = 59; over, coarse filters such as plant associa- 91%), reflecting its central location and tions and ecological processes are often spatial dominance (51%) of the study area. less tangible concepts for the public to un- Forty-eight plants (74%) were ranked ei- derstand. Fine-scale methods may more ther S1 or S2 (state-level ranks indicat- effectively conserve the species or special ing imperilment due to rarity, threats, or elements addressed but are generally too other factors) in at least one state within impractical (i.e., costly and time-intensive) the assessment area. Forty vertebrates to apply to more than a handful of taxa, es- of concern were selected for our assess- pecially across large landscapes (Noss and ment, including 17 mammals, 18 birds, and Cooperrider 1994, Haufler 1999b, Groves 4 reptiles. Among these were 7 vertebrates 2003). commonly considered sagebrush-obligate To address the inherent limitations in species: sagebrush lizard (Sceloporus gra- using only one approach, many broad-scale ciosus), greater sage-grouse (Centrocercus assessments, including those conducted by urophasianus), sage thrasher (Oreoscop- The Nature Conservancy (TNC), com- tes montanus), sage sparrow (Amphispiza bine coarse-filter (e.g., plant associations belli), Brewer’s sparrow (Spizella breweri), or species guilds) and fine-filter (e.g., spe- pronghorn (Antilocapra americana), and cies) methods (Noss 1987; Haufler 1999a, pygmy rabbit (Brachylagus idahoensis). b; Stein et al. 2000; Carignan and Villard Several vertebrate species of concern in 2002; Groves 2003; Wisdom et al. 2005a). the Wyoming Basins are either rare or For example, the conservation plan for imperiled, including black-footed ferret the Utah-Wyoming Rocky Mountains (Mustela nigripes) and Wyoming pocket Ecoregion, which lies within the bound- gopher (Thomomys clusius). aries of the WBEA (Ch. 1), identified 17 46 Species Selection – Rowland et al. 47 Artemisia communities as conservation is provided, the requirements of the entire targets (coarse filter) in addition to a suite assemblage will be met. of focal species (e.g., gray wolf [Canis lu- Criteria for selecting species may be pus]) and special elements (e.g., petiolate based on a variety of factors, including per- wormwood [A. campestris var petiolata]) ceived levels of risk to potential threats; (fine filter; Noss et al. 2001). In the Great sensitivity to disturbance; conservation Basin ecoregional assessment, Wisdom et status as indicated by state or federal lists al. (2005a) evaluated conditions for both of threatened, endangered, or sensitive sagebrush-associated species and groups species; representation of a broad range of species, with groupings based on simi- of spatial scales and ecological processes; larities in habitat associations and total current population trend; response to habitat area within various land cover management actions; cost effectiveness of types. measuring or monitoring the species; and Recognizing the advantages of combin- association with a land cover of interest ing strategies, we also used a hybrid ap- (e.g., riparian communities, sagebrush, old proach of coarse- and fine-filter strategies growth forest) (Stephenson and Calcarone for the WBEA. The primary basis of our 1999, Carignan and Villard 2002, Andel- assessment was a variant of a coarse-filter man et al. 2004, Wisdom et al. 2005b). strategy; that is, we focused on (1) identi- The state-level Comprehensive Wildlife fying and quantifying all sagebrush land Conservation Strategies use a variety of cover types within the study area and (2) approaches to identify species of concern identifying, mapping, and assessing the (see http://www.wildlifeactionplans.org/). impact of anthropogenic disturbance on For example, the Wyoming Action Plan sagebrush cover types within the study incorporated a habitat x population sta- area (Introduction). This approach al- tus matrix, in which Native Species Status lowed characterization of the entire sage- (NSS) ranks from 1 to 7 were assigned and brush ecosystem within our study area, used to select species (Wyoming Game an advantage of a coarse-filter strategy and Fish Department 2005). (Haufler 1999a). Our overall objective in selecting spe- To complement this approach and meet cies for the WBEA was to capture a broad additional WBEA objectives of identify- range of sagebrush-associated species that ing plant and wildlife species of conserva- represented multiple spatial scales and el- tion concern and assessing impacts of dis- ements of sagebrush ecosystems and were turbance on these species (Introduction), potentially sensitive to anthropogenic dis- we also selected a suite of vascular plant turbance and management actions in the and vertebrate species that are associated study area. Primary criteria for selection with sagebrush. Wisdom et al. (2005a) of species were (1) strong association with identified >350 species of conservation sagebrush ecosystems and (2) recognized concern associated with the sagebrush status of conservation concern due to de- ecosystem in the western United States; clining habitats, populations, or both. Our we used their list as a starting point for our intention was to be more inclusive than fine-filter selection, recognizing that we exclusive to ensure that we considered could not address all species of concern in all potential species of concern and their our assessment due to limitations of time habitats in sagebrush ecosystems of the and funding. Our approach resembles that study area. This inclusive approach pro- described by Marcot and Flather (2007) as vided an opportunity to evaluate species a “multiple species” strategy based on en- that may not currently be of concern but tire habitat assemblages, with the assump- may become so in the future (Wisdom et tion that if macrohabitat (i.e., sagebrush) al. 2005b). Moreover, because information 48 PART I: Characteristics of the Wyoming Basins FIG. 2.1. Criteria and decision diagram for selecting species of conservation concern for multi-species assessment in an ecoregion (from Wisdom et al. [2005a]). about populations and habitat association SELECTING SPECIES FOR is relatively scarce for many species in non- ASSESSMENT forested ecosystems such as sagebrush (Dobkin and Sauder 2004), our approach The process for selection of species increased the likelihood of evaluating spe- of concern for the WBEA followed a se- cies that are at risk but whose conservation quence of steps; species had to meet all status is not well understood. criteria in this process to be retained for The initial step in conducting the consideration (Fig. 2.1). Species with fine- WBEA was to select species of concern, grained environmental requirements were specifically vascular plants and terrestrial eliminated because of the coarse-scale vertebrates. We then acquired or created spatial data available for assessing en- range maps for vertebrates to understand vironmental conditions across the study patterns of species distribution across the area. Species with very limited geographic study area and for constraining areas for ranges,