Search Results

Knowledge of basal stresses is essential for analyzing slope stability and modeling the dynamics and erosive potential of debris flows and avalanches. Here we derive and test new algebraic formulas for calculating the shear stress τ and normal stress σ at the base of variable‐thickness granular debris masses in states of static or dynamic...

An evaluation was conducted to describe adult sockeye salmon (Oncorhynchus nerka) upstream movement patterns from Roza Dam to Cle Elum Dam in the Yakima Basin, Washington. Sockeye salmon adults that arrive at Roza Dam are currently trapped and transported upstream of Cle Elum Dam because upstream fish-passage facilities are...

Invasive species can alter ecosystem properties and cause state shifts in landscapes. Resource managers charged with maintaining landscapes require tools to understand implications of alternative actions (or inactions) on landscape structure and function. Simulation models can serve as a virtual laboratory to explore these alternatives and...

Purpose of Review: Climate change and associated ecological impacts have challenged many conventional, observation-based approaches for predicting ecosystem and landscape responses to natural resource management. Complex spatial ecological models provide powerful, flexible tools which managers and others can use to make inferences about management impacts on future, no-analog landscape conditions. However,...

Changes in the timing, magnitude, frequency, and duration of extreme hydrologic events are becoming apparent and could disrupt species assemblages and stream ecosystems across the Northeastern United States. Between August 28 and 29 of 2011, an average of 31 cm of rain from Tropical Storm Irene fell across Eastern New...

Agricultural impacts on aquatic ecosystems are well-studied, however, most research has focused on temperate regions, whereas the forefront of agricultural expansion is currently in the tropics. At the vanguard of this growth is the boundary between the Amazon and Cerrado biomes in Brazil, driven primarily by expansion of soybean and...

1. Climate change has been identified as one of the most important drivers of wildlife populations. The development of appropriate conservation strategies relies on reliable predictions of population responses to climate change, which require in-depth understanding of the complex relationships between climate and population dynamics through density dependent demographic processes....

Flood-inundation maps for a 14.5-mile reach of the Amite River and a 20.2-mile reach of the Comite River from State Highway 64 to U.S. Highway 190 were created by the U.S. Geological Survey (USGS) in cooperation with the City of Central, Louisiana. These maps, which can be accessed through an...

Managing recreational fisheries in lake-rich landscapes with diverse fish communities and anglers alike presents a social and biological challenge for managers. Understanding angler preferences is central to navigating these challenges and can aid in predicting shifts in angler behavior in response to management actions or changing fish populations. Species-specific angler...

Terrestrial ecosystems are an important sink for atmospheric carbon dioxide (CO2), sequestering ~30% of annual anthropogenic emissions and slowing the rise of atmospheric CO2. However, the future direction and magnitude of the land sink is highly uncertain. We examined how historical and projected changes in climate, land use, and ecosystem...

‘Ōhi’a lehua (Metrosideros polymorpha) is the principle tree species in forests across the Hawaiian Islands and provides critical foraging and nesting habitat for native passerines. Rapid Ohia Death (ROD), caused by the vascular wilt fungus Ceratocystis lukuohia and the canker pathogen C. huliohia, was first detected in the Puna District of Hawaii Island...

Wildfires are often viewed as destructive disturbances. We propose that when including both evolutionary and socioecological scales, most ecosystem fires can be understood as natural processes that provide a variety of benefits to humankind. Wildfires provide open habitats that enable the evolution of a diversity of shade-intolerant plants and animals...

During coastal wetland restoration, foundation plant species play a critical role in creating habitat, modulating ecosystem functions, and supporting ecological communities. Following initial hydrologic restoration, foundation plant species can help stabilize sediments and jump-start ecosystem development. Different foundation species, however, have different traits and environmental tolerances. To understand how these...

Most plant species are spatially aggregated. Local demographic and ecological processes (e.g. vegetative growth and limited seed dispersal) result in a clustered spatial pattern within an environmentally homogenous area. Spatial aggregation should be considered when modelling plant abundance data.Commonly, plant abundance is quantified by measuring cover within multiple areal plots...

The U.S. Geological Survey monitors water level (water surface elevation relative to an arbitrary datum) and measures streamflow in Alaska rivers to compute and compile river flow records for use by water resource planners, engineers, and land managers to design infrastructure, manage floodplains, and protect life, property, and aquatic resources....

AimSurrogate species can provide an efficient mechanism for biodiversity conservation if they encompass the needs or indicate the status of a broader set of species. When species that are the focus of ongoing management efforts act as effective surrogates for other species, these incidental surrogacy benefits...

Many agencies overlook the values affiliated with relatively small fisheries throughout their jurisdictions. The economic activity associated with angling visits to seven small fisheries in South Dakota was estimated using IMPLAN software. The average economic activity associated with fishing at individual lakes in 2016 was US\$35,369/lake, which was estimated to...

Fuel breaks are increasingly being implemented at broad scales (100s to 10,000s of square kilometers) in fire‐prone landscapes globally, yet there is little scientific information available regarding their ecological effects (eg habitat fragmentation). Fuel breaks are designed to reduce flammable vegetation (ie fuels), increase the safety...

Methane hydrate occurs naturally under pressure and temperature conditions that are not straightforward to replicate experimentally. Xenon has emerged as an attractive laboratory alternative to methane for studying hydrate formation and dissociation in multiphase systems, given that it forms hydrates under milder conditions. However, building reliable analogies between the two...

In the presence of a predator, prey may alter their temporal activity patterns to reduce the risk of an encounter that may induce injury or death. Prey perception of predation risk and antipredator responses may increase in the presence of dependent offspring. We conducted a camera trap study during summer...

OverviewWater is a critically important resource for the Mississippi Alluvial Plain (MAP) region, supporting a multibillion-dollar agricultural industry. There are concerns that continued withdrawals of groundwater for irrigation may decrease future water supplies. The U.S. Geological Survey has a history of conducting research in the MAP region and recently began...

Mercury (Hg) loading and methylation in aquatic systems causes a variety of deleterious effects for fish and wildlife populations. Relatively little research has focused on Hg movement into riparian food webs and how this is modulated by habitat characteristics. This study characterized differences in Hg exposure in aquatic invertebrates and...

Urbanization is a substantial force shaping the genetic and demographic structure of natural populations. Urban development and major highways can limit animal movements, and thus gene flow, even in highly mobile species. Characterizing varying species responses to human activity and fragmentation is important for maintaining genetic...

Two commonly used approaches for water quality monitoring are probabilistic and targeted. In a probabilistic approach like the US Environmental Protection Agency’s National Rivers and Streams Assessment, monitoring sites are selected using a statistically representative approach. In a targeted approach like that used by many monitoring organizations, monitoring...

Enumerating and examining marine animal carcasses is important for quantifying mortality rates and determining causes of mortality. Drifter experiments are one tool for estimating at‐sea mortality and determining factors affecting carcass drift, but they require validation to confirm drifters accurately replicate the drift characteristics of the...