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Whooping cranes (Grus americana) of the Aransas-Wood Buffalo population migrate twice each year through the Great Plains in North America. Recovery activities for this endangered species include providing adequate places to stop and rest during migration, which are generally referred to as stopover sites. To assist in recovery efforts, initial estimates of stopover site use intensity are presented, which provide opportunity to identify areas across the migration range used more intensively by whooping cranes. We used location data acquired from 58 unique individuals fitted with platform transmitting terminals that collected global position system locations. Radio-tagged birds provided 2,158 stopover sites over 10...
Species distribution modeling (SDM) is an important tool to assess the impact of global environmental change. Many species exhibit ecologically relevant intraspecific variation, and few studies have analyzed its relevance for SDM. Here, we compared three SDM techniques for the highly variable species Pinus contorta. First, applying a conventional SDM approach, we used MaxEnt to model the subject as a single species (species model), based on presence–absence observations. Second, we used MaxEnt to model each of the three most prevalent subspecies independently and combined their projected distributions (subspecies model). Finally, we used a universal growth transfer function (UTF), an approach to incorporate intraspecific...
Many changes in mammalian faunas occurred across the early (Wasatchian) to middle (Bridgerian) Eocene boundary as documented in the fossil record from the Western Interior of North America. One of the more striking changes took place within the tarsiiform primate family Omomyidae. In the early Eocene, omomyids were dominated, both in abundance and diversity, by the subfamily Anaptomorphinae. In the middle Eocene, the subfamily Omomyinae dominated in abundance, while both subfamilies were nearly equally diverse. Examination of a series of paleoecological indicators including leaf-margin analysis, cenogram analysis, ecological diversity analysis of trophic structure, the distribution and development of ancient soil...
Abstract (from http://journals.ametsoc.org/doi/10.1175/WCAS-D-16-0121.1): Much of the academic literature and policy discussions about sustainable development and climate change adaptation focus on poor and developing nations, yet many tribal communities inside the United States include marginalized peoples and developing nations who face structural barriers to effectively adapt to climate change. There is a need to critically examine diverse climate change risks for indigenous peoples in the United States and the many structural barriers that limit their ability to adapt to climate change. This paper uses a sustainable climate adaptation framework to outline the context and the relationships of power and authority,...
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Synopsis: Wind erosion control is typically needed in areas with low and variable precipitation and frequent droughts, and where high winds, high temperature and consequent high evaporation are common conditions, such as in southern Alberta. Potential average annual erosion rates from wind erosion are predicted using the wind erosion equation E= f(I, K, C, L, V) where I is the soil erodibility index, K is the soil-ridge-roughness factor, C is the climactic factor, L is the unsheltered, weighted travel distance of the wind across a field and V is the equivalent vegetated cover. Wind erosion can be controlled with one or more of the following five basic principles of wind erosion control: · Reduce field widths...
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Synopsis: Recent reports clearly indicate that odor emitted from concentrated livestock production facilities in the Midwest of the US is a significant social problem that negatively impacts rural and state economies, human health, and the quality of rural life. A potential incremental approach to dealing with livestock odor is the use of shelterbelts arranged in strategic designs near and within livestock facilities. This review outlines the various ways that shelterbelts can be effective technology which biophysically mitigates odor thereby reducing social conflict from odor nuisance. The biophysical potential of shelterbelts to mitigate livestock odor arises from the tree/shrub impacts on the central characteristics...
* 1 A classic biogeographic pattern is the alignment of diploid, tetraploid and hexaploid races of creosote bush (Larrea tridentata) across the Chihuahuan, Sonoran and Mohave Deserts of western North America. We used statistically robust differences in guard cell size of modern plants and fossil leaves from packrat middens to map current and past distributions of these ploidy races since the Last Glacial Maximum (LGM). * 2 Glacial/early Holocene (26?10 14C kyr bp or thousands of radiocarbon years before present) populations included diploids along the lower Rio Grande of west Texas, 650 km removed from sympatric diploids and tetraploids in the lower Colorado River Basin of south-eastern California/south-western...
Transportation biofuel production in the United States is currently dominated by ethanol from the grain of maize and, to a much lesser extent, biodiesel from soybeans. Although using these biofuels avoids many of the environmentally detrimental aspects of petroleum-based fossil fuels, biofuel production has its own environmental costs, largely related to fossil fuel use in converting crops to biofuels and crop cultivation itself, including ecological damages caused by nitrogen and phosphorus fertilizers, pesticides, and erosion. A new generation of biofuels derived from lignocellulosic sources offers greatly reduced environmental impacts while potentially avoiding conflicts between food and energy production. In...
Transportation biofuel production in the United States is currently dominated by ethanol from the grain of maize and, to a much lesser extent, biodiesel from soybeans. Although using these biofuels avoids many of the environmentally detrimental aspects of petroleum-based fossil fuels, biofuel production has its own environmental costs, largely related to fossil fuel use in converting crops to biofuels and crop cultivation itself, including ecological damages caused by nitrogen and phosphorus fertilizers, pesticides, and erosion. A new generation of biofuels derived from lignocellulosic sources offers greatly reduced environmental impacts while potentially avoiding conflicts between food and energy production. In...
Abstract (from http://journals.ametsoc.org/doi/abs/10.1175/WCAS-D-15-0042.1): Drought is a natural part of the historical climate variability in the northern Rocky Mountains and high plains region of the United States. However, recent drought impacts and climate change projections have increased the need for a systematized way to document and understand drought in a manner that is meaningful to public land and resource managers. The purpose of this exploratory study was to characterize the ways in which some federal and tribal natural resource managers experienced and dealt with drought on lands managed by the U.S. Department of the Interior (DOI) and tribes in two case site examples (northwest Colorado and southwest...
The influence of the Pacific decadal oscillation (PDO) on important hydroclimatic variables during years of neutral ENSO for 84 climate divisions in the western United States is analyzed from 1925 to 1998. When the 34 neutral ENSO years are split by cold (12 yr) and warm (22 yr) PDOs, the resulting winter precipitation patterns are spatially similar to those that occur during years of La Ni�a?cold PDO and, to a lesser extent, years of El Ni�o?warm PDO, respectively, although the characteristic ENSO dipole is not evident. The PDO influence is similar when the winter Palmer drought severity index is analyzed, although the core area of influence moves from the Southwest to the northern Rockies. Correlations between...
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...
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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.
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Synopsis: Wind erosion is considered a problem when the erosion level exceeds the tolerable limit for the soil or when the erosion level is great enough to damage the crops being grown. Wind erosion control must be tailored to each farming situation and may be achieved through a combination of practices that ultimately create isolated fields, the key to wind erosion control systems. Wind erosion control measures can be grouped into four components: (1) tree and shrub windbreaks; (2) annual and perennial vegetative barriers; (3) strip cropping and trap strips; and (4) crop residues and cover crops. Wind control system design involves 4 basic principles: (1) erosion rates are predicted using the wind erosion equation;...
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Synopsis: Windbreaks are a major component of successful agricultural landscapes. At the farm scale, they help control erosion and blowing snow, improve animal health and survival under winter conditions, reduce energy consumption of the farmstead, and enhance habitat diversity. At a landscape scale, they provide habitat for various types of wildlife and have the potential to contribute significant benefits to the carbon balance equation, thereby easing the economic burdens associated with climate change. The effectiveness of a windbreak is determined partially by its external structure including its height, length, orientation, continuity, width, and cross-sectional shape and partially by its internal structure...
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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.
Recent research has suggested that changes in temperature and precipitation events due to climate change have had a significant impact on the availability and timing of streamflow. In this study, monthly temperature and precipitation data collected over 29 climate divisions covering the entire Colorado River basin and monthly natural flow data from 29 U.S. Geological Survey (USGS) gauge locations along the Colorado River are investigated for trend or step changes using parametric and nonparametric statistical tests. Temperature increases are persistent (at least 10 climate divisions over 6 months in trend analysis) throughout the year over the Colorado River basin, whereas precipitation only notably increased over...
Studies of biological consequences of nuclear industrial contaminants in the environment increase in importance as the potential for exposure of wildlife populations rises. Thus, we examined levels of radiocesium (cesium-137) contamination in wood duck (Aix sponsa) eggs from a Department of Energy nuclear facility in South Carolina during 1990. Radiocesium levels in individual eggs from 5 locations on the site ranged from below detectable concentrations (<0.147 Bq/g) to a maximum of 2.21 Bq/g wet mass. Eggs from an abandoned reactor cooling reservoir contained the greatest burdens; mean egg concentrations there were more than an order of magnitude higher than those from other locations studied. Eggs from a second...
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Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in distribution and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and subtropical drylands is well constrained, whereas soil moisture and ecological droughts, which drive vegetation productivity and composition, remain poorly understood in temperate drylands. Here we show that, over the 21st century, temperate drylands may contract by a third, primarily converting to subtropical drylands,...
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Synopsis: One of the most important trends in biodiversity is the increase in the number of species as the land area increases. Botanists call this trend the species-area relationship, and it is one of the most dependable rules in biology. Many human activities on the landscape, influence species directly by disrupting their habitat, by removing other organisms upon which they may depend, or by injuring or killing them. Less direct, but in many cases equally as disruptive to the native species of an area, is the introduction of exotic species. In this study, data from published studies on flora over the last two centuries was used to produce contour maps of flora size and percentage of exotic species in North America...
map background search result map search result map Changing Patterns in the Number of Species in North American Floras. Windbreaks in North American Agricultural Systems Basic principles of wind erosion control Design and use of field windbreaks in wind erosion control systems Mitigating swine odor with strategically designed shelterbelt systems: a review. Summer Season Habitat Categories Shapefile Summer Season Habitat Suitability Index raster dataset Summer Season Habitat Categories Shapefile Summer Season Habitat Suitability Index raster dataset Changing Patterns in the Number of Species in North American Floras. Windbreaks in North American Agricultural Systems Basic principles of wind erosion control Design and use of field windbreaks in wind erosion control systems Mitigating swine odor with strategically designed shelterbelt systems: a review.