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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...
This presentation aired as part of the Great Basin LCC webinar series on October 11, 2017. Speakers included Erica Fleishman, U.C. Davis, and Jimi Gragg, Utah Division of Wildlife Resources.Description: As the distribution and abundance of non-native cheatgrass (Bromus tectorum) in the Great Basin has increased, the extent and frequency of fire in the region has increased by as much as 200%. These changes in fire regimes are associated with loss of the sagebrush (Artemisia tridentata) and native grasses and forbs in which many native animals, including Greater Sage-grouse (Centrocercus urophasianus), breed and feed. Managers have suggested changes in fire regimes, fuels treatments and post-fire restoration with...
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...
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...
A number of modeling approaches have been developed to predict the impacts of climate change on species distributions, performance and abundance. The stronger the agreement from models that represent different processes and are based on distinct and independent sources of information, the greater the confidence we can have in their predictions. Evaluating the level of confidence is particularly important when predictions are used to guide conservation or restoration decisions. We used a multi-model approach to predict climate change impacts on big sagebrush (Artemisia tridentata), the dominant plant species on roughly 43 million hectares in the western United States and a key resource for many endemic wildlife species....
Understanding how annual climate variation affects population growth rates across a species’ range may help us anticipate the effects of climate change on species distribution and abundance. We predict that populations in warmer or wetter parts of a species’ range should respond negatively to periods of above average temperature or precipitation, respectively, whereas populations in colder or drier areas should respond positively to periods of above average temperature or precipitation. To test this, we estimated the population sensitivity of a common shrub species, big sagebrush (Artemisia tridentata), to annual climate variation across its range. Our analysis includes 8175 observations of year-to-year change in...
We integrated 250-m enhanced Moderate Resolution Imaging Spectroradiometer (eMODIS) Normalized Difference Vegetation Index (NDVI) with land cover, biogeophysical (e.g., soils, topography) and climate data into regression-tree software (Cubist®). We integrated this data to create a time series of spatially explicit predictions of herbaceous annual vegetation cover in sagebrush ecosystems, with an emphasis on annual grasses. Annual grass cover in sagebrush ecosystems is highly variable year-to-year because it is strongly dependent on highly variable weather patterns, particularly precipitation timing and totals. Annual grass cover also reflects past disturbances and management decisions. We produced 17 consecutive...
On July 14, 2015 speaker Owen Baughman presented on his work in restoring areas of cheatgrass die-off.The phenomenon of complete stand failure (or die-off) of cheatgrass results in the absence of this invasive grass from the invaded site for one or more growing seasons. Our work seeks to determine if this phenomenon represents an opportunity for restoring native species. Results from two experiments at four Northern Nevada sites over three years are demonstrating that seeded native grasses can have higher success in recent die-offs when compared to seedings in sites that did not die-off. These promising findings indicate that restoring native diversity in highly-invaded systems can be facilitated by targeting die-offs...
Environmental conditions recorded at 2,256 Great Basin and Mojave Desert springs that were inventoried from the late 1980s into 2013 are summarized. These records provide information about individual springs and their spatial variability across the landscape. Insight into their changing condition is provided by records compiled at springs visited several times over more than 20 years. Although this summary considers a small proportion of springs in this region, it provides broad insight into their size, basic water chemistry, and conditions that are indicative of springs over a large portion of the southwestern US.
This publication identifies areas where big sagebrush populations are most and least vulnerable to climate change and demonstrates where continued investment in sagebrush conservation and restoration could have the most impact.
This document will assist Tribal and non-Tribal managers to guide water and water quality management. The ideas presented here are intended to help ensure that planned management activities are aligned with the priorities, goals, and needs of the Tribal community that depends upon the river system.
Natural-resource managers and other conservation practitioners are under unprecedented pressure to categorize and quantify the vulnerability of natural systems based on assessment of the exposure, sensitivity, and adaptive capacity of species to climate change. Despite the urgent need for these assessments, neither the theoretical basis of adaptive capacity nor the practical issues underlying its quantification has been articulated in a manner that is directly applicable to natural-resource management. Both are critical for researchers, managers, and other conservation practitioners to develop reliable strategies for assessing adaptive capacity. Drawing from principles of classical and contemporary research and...
On November 4, 2016, Dr. Peter Adler, Utah State University, discussed how sagebrush sensitivity to climate change varies across the region and the strengths and weaknesses of various climate modeling approaches. Healthy big sagebrush habitat is essential for the persistence of many high value conservation species across the western US. To gain confidence in predictions of climate change impacts on existing populations of big sagebrush, a research team from Utah State University compared output from four modeling approaches, each based on very different data and assumptions. These models largely agree that rising temperatures will decrease sagebrush cover and biomass in the warmest portions of the region, but increase...
Worldwide, many species are responding to ongoing climate change with shifts in distribution, abundance, phenology, or behavior. Consequently, natural-resource managers face increasingly urgent conservation questions related to biodiversity loss, expansion of invasive species, and deteriorating ecosystem services. We argue that our ability to address these questions is hampered by the lack of explicit consideration of species’ adaptive capacity (AC). AC is the ability of a species or population to cope with climatic changes and is characterized by three fundamental components: phenotypic plasticity, dispersal ability, and genetic diversity. However, few studies simultaneously address all elements; often, AC is confused...
On July 26, 2017, Bruce Wylie and Stephen Boyte, USGS, discussed their recent research mapping herbaceous annual cover in the Great Basin.The research team utilized regression tree algorithms combined with spectral and ancillary data (for elevation, soils, etc.) to achieve accuracy-focused maps. They used high-resolution satellite data (2m) to scale ground observations to levels compatible with moderate-resolution satellites (Landsat and MODIS). The speakers also discussed data access, selected journal publications and future plans during the webinar.
The exotic annual grass Bromus tectorum (cheatgrass) dominates vast acreages of rangeland in the western USA, leading to increased fire frequency and ecosystem degradation that is often irreversible. Episodic regeneration failure (“die-off”) has been observed in cheatgrass monocultures and can have negative ecosystem consequences, but can also provide an opportunity for restoration of native species and ecological function within the imperiled sagebrush steppe ecosystem. Proximate causes of cheatgrass die-off are uncertain, although several taxa of fungal soil pathogens have been implicated. Die-off occurrence is stochastic and can occur in remote areas. Thus, developing remote sensing indicators that are repeatable...
On September 29, speaker Erik Beever presented his results on pika distribution and climate change.The Great Basin is one of North America’s most physiographically complex regions, engendering both great microclimatic diversity and high levels of endemism. Although mountains comprise the majority of the Basin, their climate and wildlife are under-studied. Beever’s team is taking advantage of historical (1898-1956) surveys, 21 years of more-systematic and more-comprehensive recent surveys, and a diversity of technological and modeling advances. This information helps tackle numerous questions at the interface of how Great Basin systems work (‘basic science’) and how Basin resources may be managed and conserved, amidst...
This dataset provides a near-real-time estimate of 2017 herbaceous annual cover with an emphasis on annual grass (Boyte and Wylie. 2016. Near-real-time cheatrass percent cover in the Northern Great Basin, USA, 2015. Rangelands 38:278-284.) This estimate was based on remotely sensed enhanced Moderate Resolution Imaging Spectroradiometer (eMODIS) Normalized Difference Vegetation Index (NDVI) data gathered through June 19, 2017. This is the second iteration of an early estimate of herbaceous annual cover for 2017 over the same geographic area. The previous dataset used eMODIS NDVI data gathered through May 1 (https://doi.org/10.5066/F7445JZ9). The pixel values for this most recent estimate ranged from 0 to100% with...
On December 5, 2016, Marjorie Matocq, University of Nevada Reno, and John Kasbohm, Greater Sheldon-Hart Mountain National Wildlife Refuge, discussed functional continuity of habitat for the pygmy rabbit.Pygmy rabbits (Brachylagus idahoensis) are habitat specialists of sagebrush communities throughout the Great Basin. Overgrazing, altered fire regimes, invasive plants and energy development are expected to impact natural patterns of dispersal and gene flow among wildlife populations in sagebrush ecosystems, including pygmy rabbits. In turn, these impacts may reduce the adaptive potential and persistence of local populations. This study seeks to identify the spatial distribution of genetic variation in pygmy rabbits....