Skip to main content
Advanced Search

Filters: Tags: Nevada (X) > Extensions: Citation (X)

56 results (12ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
thumbnail
Synopsis: This study analyzed the effects of vegetation change on hydrological fluctuations in the Columbia River basin over the last century using two land cover scenarios. The first scenario was a reconstruction of historical land cover vegetation, c. 1900. The second scenario was more recent land cover as estimated from remote sensing data for 1990. The results show that, hydrologically, the most important vegetation-related change has been a general tendency towards decreased vegetation maturity in the forested areas of the basin. This general trend represents a balance between the effects of logging and fire suppression. In those areas where forest maturity has been reduced as a result of logging, wintertime...
A genecological approach was used to explore genetic variation for survival in Artemisia tridentata (big sagebrush). Artemisia tridentata is a widespread and foundational shrub species in western North America. This species has become extremely fragmented, to the detriment of dependent wildlife, and efforts to restore it are now a land manage-ment priority. Common- garden experiments were established at three sites with seed-lings from 55 source- populations. Populations included each of the three predominant subspecies, and cytotype variations. Survival was monitored for 5 years to assess dif-ferences in survival between gardens and populations. We found evidence of adap-tive genetic variation for survival. Survival...
The spread and impacts of exotic species are unambiguous, global threats to many ecosystems. A prominent example is the suite of annual grasses in the Bromus genus (Bromus hereafter) that originate from Europe and Eurasia but have invaded or are invading large areas of the Western USA. This book brings a diverse, multidisciplinary group of authors together to synthesize current knowledge, research needs, and management implications for Bromus. Exotic plant invasions are multifaceted problems, and understanding and managing them requires the biological, ecological, sociological, and economic perspectives that are integrated in this book. Knowing how well information from one geographic or environmental setting can...
Although biotic responses to contemporary climate change are spatially pervasive and often reflect synergies between climate and other ecological disturbances, the relative importance of climatic factors versus habitat extent for species persistence remains poorly understood. To address this shortcoming, we performed surveys for American pikas (Ochotona princeps) at > 910 locations in 3 geographic regions of western North America during 2014 and 2015, complementing earlier modern (1994–2013) and historical (1898–1990) surveys. We sought to compare extirpation rates and the relative importance of climatic factors versus habitat area for pikas in a mainland-versus-islands framework. In each region, we found widespread...
Bromus tectorum (cheatgrass) has widely invaded the Great Basin, U.S.A. The sporadic natural phenomenon of complete stand failure (‘die- off’) of this invader may present opportunities to restore native plants. A recent die-off in Nevada was precision-planted with seeds of the native grasses Poa secunda (Sandberg bluegrass) and Elymus elymoides (bottlebrush squirreltail), of both local and nonlocal origin, to ask: 1) Can native species be restored in recent B. tectorum die-offs? And 2) Do local and nonlocal seeds differ in performance? Additionally, we asked how litter removal and water addition affected responses. Although emergence and growth of native seeds was lower in die-off than control plots early in year...
We examined patterns of genetic variation and diversity of extant pygmy rabbit (Brachylagus idahoensis) populations across the species’ current range in Nevada and California. Our aims were to determine population genetic structure and levels of diversity across the southern portion of the species’ range. We genotyped 13 microsatellite loci from 194 fecal samples collected across 14 localities. Our Bayesian cluster analyses found 2 genetically distinct groups: 1 in the Mono Basin of California and the other encompassing all remaining Nevada Great Basin populations. Considering only the Nevada Great Basin group, we found 4 minimally divergent groups that overlap spatially with many individuals maintaining composite...
Characterizing circadian activity patterns is one of the essential steps to understanding how a species interacts with its environment. This study documented activity patterns of pygmy rabbits (Brachylagus idahoensis) in free-ranging populations at 5 sites in Nevada and California. Infrared-triggered camera systems were placed within areas occupied by populations of pygmy rabbits and operated for 1 year. The number of photographs obtained per hour was used as an index of aboveground activity. Activity was analyzed for diel and seasonal patterns as well as for differences among populations. All populations showed a bimodal diel activity pattern with most activity occurring at dawn and at dusk during all seasons....
thumbnail
Fish occurrence data to support high-resolution distribution models and test various community and macroecological hypotheses have not been available at the national scale. We present IchthyMaps, a database of high-quality historical fish occurrences covering fishes of the conterminous United States. Designed on the principles of metacommunity ecology, IchthyMaps is a compilation of presence records from atlases up to 1990, at the resolution of the 1:100,000 National Hydrography Database Plus (NHDPlus) inter-confluence stream segment, readily aggregated into hierarchically coarser units (e.g. hydrologic unit code 8-digit and 12-digit watersheds). IchthyMaps contains about 606,550 presence records for 1,038 species...
Categories: Data, Publication; Types: Citation; Tags: Alabama, Arizona, Arkansas, Biological Data, Biological sampling, All tags...
The phenomenon of cheatgrass die-off is a common and naturally- occurring stand failure that can eliminate the presence of this annual grass for a year or more, affecting tens to hundreds of thousands of acres in some years. We designed a study to determine if the temporary lack of cheatgrass caused by die-offs is a restoration opportunity. We seeded native perennial species at three die-offs in the Winnemucca, Nevada area. Native grass establishment in die-offs was almost three times higher in the first season at all sites, relative to adjacent areas without die-off. In the second season, establishment was five times higher in the die-off at two sites, and plants were notably larger in the die-off at the third...
thumbnail
Article Abstract: Although riparian and aquatic ecosystems make up a small fraction of the area in arid and semi-arid lands, they are critical for the survival of desert life. There are, however, few compendia of efforts to define the quantity of water needed to maintain these ecosystems and understand the risks and stressors to them. Through our analysis we found that 62% of the rivers examined in the deserts of the U.S. and Mexico have had just one study over the past four decades and 67% of studies used qualitative methods. Furthermore, only one-third of the 312 species catalogued in our work have been studied more than once and only 5% have been considered five or more times. The most common risks or stressors...
Rising temperatures have begun to shift flowering time, but it is unclear whether phenotypic plasticity canaccommodate projected temperature change for this century. Evaluating clines in phenological traits and the extentand variation in plasticity can provide key information on assessing risk of maladaptation and developing strategiesto mitigate climate change. In this study, flower phenology was examined in 52 populations of big sagebrush (Artemi-sia tridentata) growing in three common gardens. Flowering date (anthesis) varied 91 days from late July to lateNovember among gardens. Mixed-effects modeling explained 79% of variation in flowering date, of which 46% couldbe assigned to plasticity and genetic variation...
Content Changing aspen distribution in response to climate change and fire is a major focus of biodiversity conservation, yet little is known about the potential response of aspen to these two driving forces along topoclimatic gradients. Objective This study is set to evaluate how aspen distribution might shift in response to different climate-fire scenarios in a semi-arid montane landscape, and quantify the influence of fire regime along topoclimatic gradients. Methods We used a novel integration of a forest landscape succession and disturbance model (LANDIS-II) with a fine-scale climatic water deficit approach to simulate dynamics of aspen and associated conifer and shrub species over the next 150 years under...
Sympatric populations of Cophosaurus texanus and Callisaurus draconoides were periodically sampled from March 1973 through April 1974 at Burro Creek, Mohave County, Arizona. Callisaurus were also sampled at Rock Valley, Nye County, Nevada. Sex ratios were skewed in favor of males in the adult Cophosaurus but were equal in both adult populations of Callisaurus. Both species became sexually mature as yearlings. Mean clutch sizes were 3.55 (+/- 0.83) for Cophosaurus, and 4.25 (+/- 1.08) and 5.07 (+/- 1.33) for Callisaurus at Burro Creek and Rock Valley respectively. Evidence of multiple clutches was exhibited by both species. Egg weight/body weight ratios for both species and clutch weight/body weight ratios for Cophosaurus...
thumbnail
This raster represents a continuous surface of sage-grouse habitat suitability index (HSI) values for Nevada during summer, which is a surrogate for habitat conditions during the sage-grouse brood-rearing period.
thumbnail
Successful implementation of environmental flow projects depends on land and water managers having clear objectives and access to reliable data. This guidebook provides information on a variety of methods that can be utilized under different fiscal or temporal constraints to determine and implement appropriate environmental flow targets. Based on evidence from cases focused in the Southwestern United States and Northern Mexico, steps are suggested to help ensure maintenance of flows under uncertain future natural and socioeconomic conditions. The importance of education and engagement to increase acceptance of environmental flows based projects and gain key player and community buy in is described. Limitations on...
Land managers are responsible for developing effective strategies for conserving and restoring Great Basin ecosystems in the face of invasive species, conifer expansion, and altered fire regimes. A warming climate is magnifying the effects of these threats and adding urgency to implementation of management practices that will maintain or improve ecosystem functioning. This Factsheet Series was developed to provide land managers with brief summaries of the best available information on contemporary management issues to facilitate science delivery and foster effective management. Each peer-reviewed factsheet was developed as a collaborative effort among knowledgeable scientists and managers. The series begins with...
Alpine and subalpine plant species are of special interest in ecology and ecophysiology because they represent life at the climate limit and changes in their relative abundances can be a bellwether for climate-change impacts. Perennial life forms dominate alpine plant communities, and their form and function reflect various avoidance, tolerance, or resistance strategies to interactions of cold temperature, radiation, wind, and desiccation stresses that prevail in the short growing seasons common (but not ubiquitous) in alpine areas. Plant microclimate is typically uncoupled from the harsh climate of the alpine, often leading to substantially warmer plant temperatures than air temperatures recorded by weather stations....
thumbnail
Conclusions: Report identifies regional patterns of habitat disturbance, land use practices, and population trends relative to greater sage-grouse. In general, the most important landscape characteristics influencing sage-grouse populations are the proximity of leks (areas in which males perform to nesting habitat for and The report examined findings from studies that indicate several area and distance specific conservation thresholds for maintaining viable sage-grouse habitat. Thresholds/Learnings: Male sage-grouse prefer sod-forming grasses or bare ground for leks; female sage-grouse prefer dense sagebrush stands surrounding leks for nesting; gentle terrain characterized by <10% slope; <5% of existing sagebrush...
thumbnail
This shapefile represents habitat suitability categories (High, Moderate, Low, and Non-Habitat) derived from a composite, continuous surface of sage-grouse habitat suitability index (HSI) values for Nevada and northeastern California during summer¸ which is a surrogate for habitat conditions during the sage-grouse brood-rearing period.
map background search result map search result map Estimated potential for sage-grouse movement Effects of land cover change on streamflow in the interior Columbia River Basin (USA and Canada). Conservation Assessment of Greater Sage-Grouse and Sagebrush Habitats Historical Stream Fish Distribution Database for the Conterminous United States (1950-1990): IchthyMaps Summer Season Habitat Categories Shapefile Summer Season Habitat Suitability Index raster dataset Desert Flows Methodology Guidebook Environmental flows in the desert rivers of the United States and Mexico: Synthesis of available data and gap analysis Estimated potential for sage-grouse movement Summer Season Habitat Categories Shapefile Summer Season Habitat Suitability Index raster dataset Effects of land cover change on streamflow in the interior Columbia River Basin (USA and Canada). Desert Flows Methodology Guidebook Environmental flows in the desert rivers of the United States and Mexico: Synthesis of available data and gap analysis Conservation Assessment of Greater Sage-Grouse and Sagebrush Habitats Historical Stream Fish Distribution Database for the Conterminous United States (1950-1990): IchthyMaps