Search Results

Climate change poses multiple threats to biodiversity, and has already caused demonstrable impacts. We summarize key results from a recent national assessment of observed climate change impacts to terrestrial, marine, and freshwater ecosystems in the United States, and place results in the context of commonly articulated hypotheses about ecosystem response...

Recent work indicates that the establishment of bigheaded carps (Hypophthalmichthys spp.) in the United States has led to a reduction in condition of native planktivores and may detrimentally affect other trophic levels by altering the base of aquatic food webs. We used fatty acids to evaluate potential effects of bigheaded...

Large tributaries may help sustain large-river fish populations by mitigating fish-habitat losses within the highly modified great rivers of the Mississippi River basin. These tributaries are likely most beneficial for fish species specializing on non-degraded large-river habitat for some portion of their life histories. Few great-river tributaries, however, have been...

Recurring drought and grazing are ecological drivers of semi-arid grasslands on the Southern High Plains, USA; however, ecological drivers are currently undergoing human-induced alterations, which likely have implications for wildlife. We used the lesser prairie-chicken (Tympanuchus pallidicinctus), an iconic grouse species that exhibits a boom-bust life history strategy, on the...

A history of overexploitation and industrialization of riverine habitats has impacted the Shortnose Sturgeon Acipenser brevirostrum, leading this species to become one of the earliest listed under the U.S. Endangered Species Act. The present understanding of Shortnose Sturgeon spatial ecology is based on observations from a limited number of Atlantic coastal...

Whitebark pine (Pinus albicaulis Engelm.) has recently experienced high mortality due to multiple stressors, and future population viability may rely on natural regeneration. We assessed whitebark pine seedling densities throughout the US Rocky Mountains and identified stand, site, and climatic variables related to seedling presence based on data from 1,217...

Trap and haul programs are used to conserve fish populations by circumventing high mortality locations or events, and enhancing population abundance by reintroducing fish to historical habitats and mitigating for fish passage limitations. Spring run Chinook Salmon are transported in trucks upstream of barrier dams in Willamette River Tributaries...

Effective conservation of endangered North Atlantic right whales (Eubalaena glacialis) requires information about their spatio-temporal distribution. Understanding temporal distribution is particularly important, because a portion of the population migrates between high latitude summer feeding grounds off the northeastern U.S. and Canadian Maritimes coasts and lower latitude calving and wintering grounds...

Fecal contamination by human and animal pathogens, including viruses, bacteria, and protozoa, is a potential human health hazard, especially with regards to drinking water. Pathogen occurrence in groundwater varies considerably in space and time, which can be difficult to characterize as sampling typically requires hundreds of liters...

In most drylands, biological soil crusts (biocrusts), an assemblage of lichens, bryophytes, fungi, green algae, and cyanobacteria, are critical to healthy ecosystem function. However, they are extremely sensitive to disturbance and attempts to facilitate their recovery have had variable success. In this study, we applied soil amendments designed to improve...

The upper beach, between the astronomical high tide and the dune-toe, supports habitat and recreation along many beaches, making predictions of upper beach change valuable to coastal managers and the public. We developed and tested a Bayesian network (BN) to predict the cross-shore position of an upper beach elevation contour...

Translating the ever-increasing wealth of information on microbiomes (environment, host, or built environment) to advance the understanding of system-level processes is proving to be an exceptional research challenge. One reason for this challenge is that relationships between characteristics of microbiomes and the system-level processes they influence are often evaluated in...

Morphological change in river channels is frequently evaluated in the context of mass balance sediment budgets. In a closed sediment budget, measurements of sediment influx and efflux are coupled with measured changes in channel topography to provide both spatial...

Streamflow time series are commonly derived from stage‐discharge rating curves, but the uncertainty of the rating curve and resulting streamflow series are poorly understood. While different methods to quantify uncertainty in the stage‐discharge relationship exist, there is limited understanding of how uncertainty estimates differ between methods due...

Accelerating sea-level rise and human impacts to the coast (e.g., altered sediment supply and hydrology, nutrient loading) influence the accumulation of sediment and organic matter, and thereby impact the ability of coastal tidal wetlands to maintain an elevation consistently within the vegetation growth range. Critical components of marsh sustainability are...

Physical properties of the sediment directly overlying a gas hydrate reservoir provide important controls on the effectiveness of depressurizing that reservoir to extract methane from gas hydrate as an energy resource. The permeability of overlying sediment determines if a gas hydrate reservoir’s upper contact will provide an effective seal...

Mixtures of DNA from multiple contributors present a novel opportunity to count individuals to inform fish and wildlife ecology.We apply a likelihood-based framework to estimate the number of contributors to a DNA mixture for ecological applications. We then assess the performance of DNA mixture estimation through a combination of...

The incidental take of golden eagles (Aquila chrysaetos) as a result of wind energy development requires some form of compensatory mitigation. Although several options have been proposed, only one has been formerly accepted and implemented, and the lack of options can limit the permit...

Widespread hydrologic alteration creates a need for tools to assess ecological impacts to streams that can be applied across large geographic scales. A regional framework for biologically based flow management can help catchment managers prioritise streams for protection, evaluate impacts of disturbance or interventions and provide a starting point for...

Spatial and temporal variability in factors influencing mangrove establishment and survival affects the distribution of mangrove, particularly near their latitudinal limit, where mangrove expansion into saltmarsh is conspicuous. In this paper the spatial variability in mangrove distribution and variability in factors influencing mangrove establishment and survival during the Quaternary period...

Airborne microorganisms in the upper troposphere and lower stratosphere remain elusive due to a lack of reliable sample collection systems. To address this problem, we designed, installed, and flight-validated a novel Aircraft Bioaerosol Collector (ABC) for NASA's C-20A that can make collections for microbiological research investigations up to altitudes of...

Investigating the reproductive ecology of naturalized species provides insights into the role of the source population's characteristics vs. post‐release adaptation that influence the success of introduction programmes. Introduced and naturalized Mallards Anas platyrhynchos are widely established in New Zealand (NZ), but little is known regarding their reproductive ecology. We evaluated the nesting...

Knowledge of landscape and regional circumstances where conservation programs are successful on working lands in agricultural production are needed. Converting marginal croplands to grasslands using conservation programs such as the United States Department of Agriculture Conservation Reserve Program (CRP) should be beneficial for many grassland‐obligate wildlife species; however, addition of...

Effects of discharge variability on point-bar sedimentation are not well documented, although resulting changes in flow patterns are well known. This paper focuses on a meander of Powder River in Montana (USA). In May 1978, Powder River had a 50-year recurrence flood, which caused...

Coastal marine habitats become contaminated with the munitions constituent, Hexahydro-1,3,5-trinitro-1,3,5-trazine (RDX), via military training, weapon testing and leakage of unexploded ordnance. This study used 15N labeled RDX in simulated aquarium-scale coastal marine habitat containing seawater, sediment, and biota to track removal pathways from surface water including sorption onto particulates, degradation to nitroso-triazines and mineralization to dissolved...