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In a landscape, abiotic features, such as boulders, influence microhabitats and consequently affect patterns of vegetation. We hypothesized that boulders in the foothills of the Wasatch Mountains east of Provo, Utah, affected the growth patterns of netleaf hackberry (Celtis reticulata) by providing shade on their north faces. To test this hypothesis, we set up 3 transects 6 m wide and up to 50 m long. Along these transects, we measured all hackberries taller than 30 cm (n = 249). We recorded whether the hackberries grew within 0.5 m of a boulder that was at least 0.5 m along one dimension. We found that hackberries at our study site were more likely to be associated with boulders (n = 225; 90.4%) than to be growing alone (n = 24; 10.7%) (x2 = 162.25, df = 1, P < 0.001). For each hackberry associated with a boulder, we took a direction bearing from the center of the boulder to the place where the hackberry was rooted. We found that hackberries associated with boulders were more likely to grow near the south (n = 92; 40.9%) side than near the north (n = 35; 15.6%), west (n = 55; 24.4%), or east sides (n = 43; 19.1%) (x2 = 33.90, df = 3, P < 0.001). These results suggest that boulders influence patterns of hackberry growth and may actually provide thermal radiation that melts snow in the Wasatch foothills, rather than shade protection as we had originally hypothesized. [ABSTRACT FROM AUTHOR]

Aplodontia rufa (mountain beaver) is considered the sole remaining extant genus and species of an ancient lineage that once broadly inhabited the Great Basin and is now restricted to the Pacific Northwest and portions of California and Nevada. Aplodontia rufa californica in Nevada is distributed patchily at the edge of mountain beaver distribution. Due to concern over the status of these populations this subspecies is listed in Nevada as sensitive. The Nevada Department of Wildlife is concerned about the status of Aplodontia rufa californica populations scattered across areas of central western Nevada and has worked to gain an understanding of the subspecies' current distribution and numbers. Because there is a lack of a thorough genetic analysis of these populations in Nevada, this study aims to assess the evolutionary relationships and connectivity of populations within Nevada and California. Therefore, we sampled each of the 9 known localities of Aplodontia rufa in Nevada, as well as 4 sites from the type locality region of the central Sierra Nevada Mountains of California for comparison, using mitochondrial DNA for phylogenetic and network analyses. Additionally, we used microsatellite markers to assess connectivity of populations within Nevada and to proximate California populations. We found that Nevada populations share mitochondrial DNA haplotypes with California populations and therefore belong to the same subspecies. Furthermore, we found evidence of gene flow between Nevada and California populations. Within Nevada, we detected population differentiation that suggested fragmented populations with restricted connectivity. The results of this study will allow Nevada wildlife managers to develop targeted management strategies to enhance connectivity between populations where it is lacking, to protect connectivity that exists, and also to conserve habitat required by this species. This study increases our understanding of this unique and ancient rodent species at the edge of its distribution. [ABSTRACT FROM AUTHOR]

We describe 46 new site records documenting occupancy by American pika (Ochotona princeps) at 21 locations from 8 mountain regions in the western Great Basin, California, and Nevada. These locations comprise a subset of sites selected from regional surveys to represent marginal, isolated, or otherwise atypical pika locations, and to provide information for assessing environmental tolerance limits. Several locations are known from historic observations (Madeline Plain, Bodie Mtns., Wassuk Mtns., Mono Craters) and are included here to update current status. Site elevations range from 1848 m to 3392 m; relative to the broad range of pika sites in the region, the new locations have climates that are 2-4 °C warmer and receive approximately half the annual precipitation. Sites are located in lava flows and domes, inselbergs (isolated, rocky exposures on a small hill), eroding bedrock, rock-glacier till, talus slopes, and anthropogenic roadbed armaments and mining ore dumps. Several sites are situated in uncommon vegetation contexts, for example, montane desert scrub communities or locations where vegetation adjacent to taluses is sparse or lacking. Proximity to surrounding pika habitats (as a measure of marginality) was evaluated based on relative talus distribution patterns for 0.5-km, 2.5-km, and 5.0-km circular areas nested around each site. Seven idealized, schematic spatial patterns were used to assess potential connectivity among sites, ranging from "island" (no other talus within the respective areas) to "even" (many talus patches regularly distributed). Applying this approach to the 21 sites demonstrated a simple method for qualitatively assessing pika habitat relative to dispersal potential and metapopulation viability and also revealed complexities of biogeographic patterns related to marginality. [ABSTRACT FROM AUTHOR]

Understanding anthropogenic and environmental factors that influence seasonal habitat selection is critical in establishing conservation objectives for wildlife populations. However, many resource selection studies provide inferences only for single seasons, potentially masking factors essential to populations during other times of the year. Our objective was to model elk (Cervus elaphus) habitat selection for 4 seasons to identify factors influencing selection within and across seasons. Using aerial relocation data, we evaluated seasonal habitat selection for 46 radio-marked, migratory adult female elk in a 6123-km2 landscape in north central Utah, USA, from 1993 to 1997. We evaluated habitat use and availability within estimated seasonal range boundaries by using binary logistic regression to model habitat selection. Habitat use was measured as a response to predictor variables collected from analysis regions around elk locations. Habitat use was compared to habitat availability by measuring those same variables collected from randomly located analysis regions. Our results showed that roads, topography, and vegetation cover influenced elk habitat selection within and across seasons. Roads did not influence elk habitat selection in spring; rather, elk selected areas with aspen (Populus tremuloides) at higher elevations. In summer, elk selected forage-rich habitats, particularly aspen and mountain brush at higher elevations and on cooler aspects. In fall, elk selected sites with steeper slopes at higher elevations in areas with greater cover of aspen and mountain brush than was available in seasonal range boundaries. In winter, elk selected sagebrush (Artemisia spp.)-meadow cover on steeper slopes at lower elevations away from major roads. The full array of seasonal habitat selection patterns we found provides managers with greater options for setting conservation objectives for elk on a year-round basis. [ABSTRACT FROM AUTHOR]

Subalpine meadows are some of the most ecologically important components of mountain landscapes, and primary productivity is important to the maintenance of meadow functions. Understanding how changes in primary productivity are associated with variability in moisture and temperature will become increasingly important with current and anticipated changes in climate. Our objective was to describe patterns and variability in aboveground live vascular plant biomass in relation to climatic factors. We harvested aboveground biomass at peak growth from four 64-m2 plots each in xeric, mesic, and hydric meadows annually from 1994 to 2000. Data from nearby weather stations provided independent variables of spring snow water content, snow-free date, and thawing degree days for a cumulative index of available energy. We assembled these climatic variables into a set of mixed effects analysis of covariance models to evaluate their relationships with annual aboveground net primary productivity (ANPP), and we used an information theoretic approach to compare the quality of fit among candidate models. ANPP in the xeric meadow was negatively related to snow water content and thawing degree days and in the mesic meadow was negatively related to snow water content. Relationships between ANPP and these 2 covariates in the hydric meadow were not significant. Increasing snow water content may limit ANPP in these meadows if anaerobic conditions delay microbial activity and nutrient availability. Increased thawing degree days may limit ANPP in xeric meadows by prematurely depleting soil moisture. Large withinyear variation of ANPP in the hydric meadow limited sensitivity to the climatic variables. These relationships suggest that, under projected warmer and drier conditions, ANPP will increase in mesic meadows but remain unchanged in xeric meadows because declines associated with increased temperatures would offset the increases from decreased snow water content. [ABSTRACT FROM AUTHOR]

The Dusky Great Horned Owl (Bubo virginianus saturatus) of the Pacific Northwest region of North America is generally considered to be nonmigratory. Here we report a specimen of a Dusky Great Horned Owl that was salvaged in New Mexico and identified based on comparison of its plumage with a large series of museum skins. We attempted to corroborate this identification by comparing mitochondrial DNA sequences between the specimen and a representative sample of 5 Great Horned Owl subspecies from western North America. This analysis revealed minimal mitochondrial genetic variation and no evidence of population genetic structure, suggesting that the marked plumage differences among subspecies evolved since the late Pleistocene. To evaluate the possibility that the salvaged specimen was transported after death, we analyzed its stomach contents. The stomach contained remains of a desert cottontail (Sylvilagus audubonii), a locally abundant rabbit species in central New Mexico. The mitochondrial haplotype of the rabbit was novel but closely related to haplotypes found in New Mexico and west Texas. This is the first report of long distance movement in the Pacific Northwest subspecies of Great Horned Owl, though we cannot rule out the possibility of anomalous melanism. Although there is tremendous potential for forensic-style phylogeographic investigation of animal movements, this study illustrates that sequence databases are not yet adequate to the task, even for common North American vertebrate species. [ABSTRACT FROM AUTHOR]

Research has shown that there are more than 30 differently named leadership styles, ranging from micro-management to hands-off, each with its own proponents. Six, however, stand out as most commonly found in business: authoritarian, democratic, transformational, laissez-faire, servant, and situational. A review of the experiences of six leaders who embody these styles reveals that each mode of operating has its pros and cons; there is no single best approach. Being aware of one's leadership style and that of others makes it possible to leverage strengths and compensate for weaknesses and to properly match individuals to a particular role or task-for the good of the entire organization. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Introduction. For this research work, the acid whey produced by Oaxaca cheese industry in a UASB reactor was used. The reactor was subjected to three constant charges and three punctual charges of the whey. The reactor had a nominal capacity of 2.9 L with 1.9 days of hydraulic retention with an upward flow and a sludge blanket of 40% of the reactor's volume. Objective. Evaluate the behavior of the UASB reactor with three different charges of whey. Materials and methods. Three different constant charges of whey were used (5200, 7800 and 10500 mg CDO/L each one) during 22 days, and punctual charges of 32000, 47000 and 65000 mg DQO/L per day of whey, for each one, during 24 hours. Both the influent and the effluent were determined: total of sugars, volatile fatty acids (VFA's) protein, pH, methane and CDO. Results. The findings demonstrated that in the constant charges used the removal efficiency of CDO was 26 %, and for the punctual charges was 57 %. The sugar degradation efficiency was 95% for the constant and the punctual charges. For the protein, the removal efficiencies in the constant charges were above 27 % and for the punctual charges the efficiency was 46 %. Conclusion. The values of volatile fatty acids and methane were all within the limits for a good functioning of the reactor. Nevertheless, the pH had acid values below the ones recommended. [ABSTRACT FROM AUTHOR]

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