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The Wild and Scenic reach of the Missouri River has a narrow fringe of plains cottonwood (Populus deltoides monilifera) that is highly valued for wildlife habitat and riparian-based recreation activities. Despite an abundant seed source, however, seedling survival is limited. The Bureau of Land Management deems adequate cottonwood regeneration an important land and water management objective for this reach. FORT scientists are evaluating the influence of summer grazing in conjunction with flow regimes as factors in cottonwood seedling establishment and survival. Managers can use this information to help resolve the relative contributions and interactions among the different factors affecting cottonwood regeneration.
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Increasing temperatures and decreasing precipitation threaten the persistence of the Rio Grande cutthroat trout, the southernmost subspecies of cutthroat trout, found only in parts of New Mexico and Colorado. This subspecies appears to be more vulnerable to drought than more northern subspecies, because it occupies small and fragmented streams which are at greater risk of drying up during drought. Most notably, in 2002 drought in the Southwest resulted in the loss of 14 different Rio Grande cutthroat trout populations – about 10% of the total population. While it is known that drought is having an effect on Rio Grande cutthroat trout, the specific ways in which individuals and populations are affected by drought...
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Population growth and decline are particularly sensitive to changes in three key life-history parameters: annual productivity, juvenile survival, and adult survival. However, for many species these parameters remain unknown. For example, although grassland songbirds are imperiled throughout North America, for this guild, only a small number of studies have assessed these parameters. From 2002 to 2006, in the agricultural landscape of the Champlain Valley of Vermont and New York, USA, we studied Savannah Sparrow (Passerculus sandwichensis) and Bobolink (Dolichonyx oryzivorus) demography on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- to mid-July; (2) middle-hayed fields...
Community energy initiatives offer a potentially important means for reshaping the electrical system in a manner compatible with emissions reduction goals. Many such initiatives, however, focus upon top-down, institutionally structured approaches that understand community residents as atomistic, economically motivated, and minimally engaged. This paper examines a number of case studies that are based upon a bottom-up approach rooted in a civic culture that seeks to maximize the capacities of an active and engaged citizenry. The paper focuses upon two mutually dependent issues: first, recruiting community members, and second, sustaining their participation.
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Riparian and aquatic ecosystems along the Bill Williams River in Arizona are extremely dynamic and responsive to patterns of streamflow release from Alamo Dam. Land and water managers along the river have been implementing managed streamflow releases from Alamo Dam to promote biological diversity downstream without interfering with other uses of the river corridor. To inform adaptive management and guide future reservoir operations, there is a need for scientific research and monitoring regarding the river system's response to these managed streamflows. The objective of this study is to evaluate responses of the Bill Williams River ecosystem—including changes in channel morphology, woody and herbaceous riparian...
Abstract (from http://www.sciencedirect.com/science/article/pii/S0380133014002597): Fish stock-recruitment dynamics may be difficult to elucidate because of nonstationary relationships resulting from shifting environmental conditions and fluctuations in important vital rates such as individual growth or maturation. The Great Lakes have experienced environmental stressors that may have changed population demographics and stock-recruitment relationships while causing the declines of several prey fish species, including rainbow smelt (Osmerus mordax). We investigated changes in the size and maturation of rainbow smelt in Lake Michigan and Lake Huron and recruitment dynamics of the Lake Michigan stock over the past...
Abstract (from http://www.srmjournals.org/doi/abs/10.2111/REM-D-13-00079.1): Big sagebrush, Artemisia tridentata Nuttall (Asteraceae), is the dominant plant species of large portions of semiarid western North America. However, much of historical big sagebrush vegetation has been removed or modified. Thus, regeneration is recognized as an important component for land management. Limited knowledge about key regeneration processes, however, represents an obstacle to identifying successful management practices and to gaining greater insight into the consequences of increasing disturbance frequency and global change. Therefore, our objective is to synthesize knowledge about natural big sagebrush regeneration. We identified...
Community energy initiatives offer a potentially important means for reshaping the electrical system in a manner compatible with emissions reduction goals. Many such initiatives, however, focus upon top-down, institutionally structured approaches that understand community residents as atomistic, economically motivated, and minimally engaged. This paper examines a number of case studies that are based upon a bottom-up approach rooted in a civic culture that seeks to maximize the capacities of an active and engaged citizenry. The paper focuses upon two mutually dependent issues: first, recruiting community members, and second, sustaining their participation.
Invasion by nonnative brook trout (Salvelinus fontinalis) often results in replacement of cutthroat trout (Oncorhynchus clarki) in the inland western United States, but the underlying mechanisms are not well understood. We conducted a four-year removal experiment to test for population-level mechanisms (i.e., changes in recruitment, survival, emigration, and immigration) promoting invasion success of brook trout and causing decline of native Colorado River cutthroat trout (O. c. pleuriticus). We chose 700–1200 m segments of four small mountain streams where brook trout had recently invaded cutthroat trout populations, two each at mid elevation (2500–2700 m) and high elevation (3150–3250 m), and annually removed...
Flannelmouth sucker, Catostomus latipinnis, a fish endemic to the Colorado River basin in the western United States, appears to experience poor recruitment to adult size in the Colorado River, downstream of Glen Canyon Dam. Lack or impermanence of rearing areas for young-of-year (YOY) fish is hypothesized to be the problem. Knowing the importance of tributary mouths as rearing areas in other river systems, we studied use of the mouth of the Paria River, a tributary of the Colorado River, by YOY flannelmouth suckers, and the availability of rearing area in the mouth at different flow levels in the Colorado River in 1996 and 1997. We also examined the relationship between flash floods in the Paria River and catch-per-unit-effort...
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Population dynamics and the impacts of disease are important when trying to elucidate the causes behind amphibian population declines. Declines of boreal toads, documented in Rocky Mountain National Park, are coincident with the detection of the amphibian chytrid fungus (Batrachochytrium dendrobatidis). Long-term studies that track population parameters such as recruitment and survival assist in understanding the dynamics of particular populations. However, studies of habitat use by boreal toads (an endangered species in the State of Colorado) and wood frogs (a species recently delisted as threatened in the State of Colorado) in the southern Rocky Mountains are limited. Few quantitative data are available about...
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Energy development in the Intermountain West is intensifying rapidly, which may have profound effects on the region's wildlife and vegetative communities. The Mountain Plover, whose populations have declined precipitously over the last 30 years, has been proposed for, but precluded from, listing under the Endangered Species Act; thus, many natural resource agencies (including the Bureau of Land Management) and other entities list it as a species of special concern and are collaborating in their efforts to better understand which factors may be contributing to the species' decline. In Wyoming, where energy development and extraction are especially intense, there is an immediate need for information about measures...
Over the past 80 years, willow communities have declined dramatically in Yellowstone's northern winter range. Recent sampling data, however, indicate changes in elk distribution and herbivory (i.e., patterns in vegetation structure) since the 1995 reintroduction of wolves. This work is designed to determine the extent of the apparent release — in both height and area — of willows across Yellowstone's northern range by (1) mapping willow distribution and (2) assessing the number of thickets established post-wolf versus pre-wolf. Scientists are also documenting the effects of willow thicket formation and post-wolf restoration on ecosystem processes, nutrient inputs to the ecosystem, plant community structure and microclimate,...
In the shortgrass steppe region of North America there is a controversy about the ability of the dominant species to recruit from seedlings. The prevailing view is that Bouteloua gracilis is incapable of recruitment from seedlings in areas receiving <380 mm of annual precipitation. A common explanation for this situation is that environmental conditions permitting seedling establishment are infrequent. To assess the frequency of environmental conditions appropriate for the recruitment of B. gracilis we used a soil water simulation model and long-term climatic data in conjunction with detailed information about the ecophysiological requirements for seed germination and growth of seminal and adventitious roots. We...
Flow regulation effects on floodplain forests in the semi-arid western United States are moderately well understood, whereas effects associated with changes in floodplain land use are poorly documented. We mapped land cover patterns from recent aerial photos and applied a classification scheme to mainstem alluvial floodplains in 10 subjectively selected 4th order hydrologic units (subbasins) in the Upper Colorado River Basin (UCRB) in order to document land use patterns (floodplain development) and assess their effects on Fremont cottonwood forest (CF) regeneration. Three of the mainstem rivers were unregulated, five were moderately regulated and two were highly regulated. We classified polygons as Undeveloped (with...
Community energy initiatives offer a potentially important means for reshaping the electrical system in a manner compatible with emissions reduction goals. Many such initiatives, however, focus upon top-down, institutionally structured approaches that understand community residents as atomistic, economically motivated, and minimally engaged. This paper examines a number of case studies that are based upon a bottom-up approach rooted in a civic culture that seeks to maximize the capacities of an active and engaged citizenry. The paper focuses upon two mutually dependent issues: first, recruiting community members, and second, sustaining their participation.
Community energy initiatives offer a potentially important means for reshaping the electrical system in a manner compatible with emissions reduction goals. Many such initiatives, however, focus upon top-down, institutionally structured approaches that understand community residents as atomistic, economically motivated, and minimally engaged. This paper examines a number of case studies that are based upon a bottom-up approach rooted in a civic culture that seeks to maximize the capacities of an active and engaged citizenry. The paper focuses upon two mutually dependent issues: first, recruiting community members, and second, sustaining their participation.


map background search result map search result map Grassland songbird survival and recruitment in agricultural landscapes: implications for source-sink demography. Boreal Toad and Wood Frog Demographics Evaluation of the Effects of Energy Development on Mountain Plovers in Wyoming Missouri River Cottonwood Demography Managed Streamflow and the Ecology of the Bill Williams River The Effects of Drought on Rio Grande Cutthroat Trout: The Role of Stream Flow and Temperature Grassland songbird survival and recruitment in agricultural landscapes: implications for source-sink demography. The Effects of Drought on Rio Grande Cutthroat Trout: The Role of Stream Flow and Temperature Evaluation of the Effects of Energy Development on Mountain Plovers in Wyoming Boreal Toad and Wood Frog Demographics Managed Streamflow and the Ecology of the Bill Williams River Missouri River Cottonwood Demography