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Filter Total Items: 170199

Low flows from drought and water use reduced total dissolved solids fluxes in the Lower Colorado River Basin between 1976 to 2008

Study area:We evaluated the Virgin, Verde, Salt, and Gila Rivers in the Lower Colorado River Basin. The watersheds have extents in Arizona, Utah, New Mexico, US and Sonora, MX.Study focus:We calculated trends in total dissolved solids (TDS) concentrations and fluxes with the Weighted Regressions on Time, Discharge and Season model. The modeling framework leverages daily streamflow and discrete wat
Authors
Annie L. Putman, Hannah Erin Mcilwain, Christine Rumsey, Thomas M. Marston

Insight into sources of benzene, TCE, and PFOA/PFAS in groundwater at Naval Air Station Whiting Field, Florida, through numerical particle-tracking simulations

Past waste-disposal activities at Naval Air Station Whiting Field (NASWF) have led to elevated concentrations of contaminants in the underlying sand and gravel aquifer. Contaminants include two of the most commonly detected chemicals in groundwater in many countries (benzene and trichloroethylene (TCE)) and the “forever chemicals” per- and poly-fluoroalkyl substances (PFAS) such as perfluorooctano
Authors
Eric Swain, James E. Landmeyer, Michael A. Singletary, Shannon E. Provenzano

The post-emergence period for denning polar bears: Phenology and influence on cub survival

Among polar bears (Ursus maritimus), only parturient females den for extended periods, emerging from maternal dens in spring after having substantially depleted their energy reserves during a fast that can exceed 8 months. Although den emergence coincides with a period of increasing prey availability, polar bears typically do not depart immediately to hunt, but instead remain at the den for up to
Authors
Erik Andersen, Ryan R. Wilson, Karyn D. Rode, George M. Durner, Todd C. Atwood, David Gustine

Characterization of change in tree cover state and condition over the conterminous United States

Variability in the effects of disturbances and extreme climate events can lead to changes in tree cover over time, including partial or complete loss, with diverse ecological consequences. It is therefore critical to identify in space and time the change processes that lead to tree cover change. Studies of change are often hampered by the lack of data capable of consistently detecting different ty
Authors
Francis K Dwomoh, Roger F. Auch

Implementation of the CREED approach for environmental assessments

Environmental exposure data are a key component of chemical and ecological assessments, supporting and guiding environmental management decisions and regulations. Measures taken to protect the environment based on exposure data can have social and economic implications. Flawed information may lead to measures being taken in the wrong place or to important action not being taken. Although the advan
Authors
Carolina Di Paolo, Irene Bramke, Jenny Stauber, Caroline Whalley, Ryan R. Otter, Yves Verhaegen, Lisa H. Nowell, Adam C. Ryan

Analysis adapted from text mining quantitively reveals abrupt and gradual plant-community transitions after fire in sagebrush steppe

ContextPlant communities vary both abruptly and gradually over time but differentiating between types of change can be difficult with existing classification and ordination methods. Structural topic modeling (STRUTMO), a text mining analysis, offers a flexible methodology for analyzing both types of temporal trends.ObjectivesOur objectives were to (1) identify post-fire dominant sagebrush steppe p
Authors
Cara Applestein, Christopher R. Anthony, Matthew Germino

River control points for algal productivity revealed by transport analysis

Measurement of planktonic chlorophyll-a—a proxy for algal biomass—in rivers may represent local production or algae transported from upstream, confounding understanding of algal bloom development in flowing waters. We modeled 3 years of chlorophyll-a transport through a 394-km portion of the Illinois River and found that although algal biomass is longitudinally widespread, most net production occu
Authors
Noah Schmadel, Judson Harvey, Jay Choi, Sarah M. Stackpoole, Jennifer L. Graham, Jennifer C. Murphy

Accurately characterizing climate change scenario planning in the U.S. National Park Service: Comment on Murphy et al. 2023

We more accurately locate the boundary between current practice and research priorities regarding climate change scenario planning in U.S. federal land management agencies by supplementing the characterization in a recent article (“Understanding perceptions of climate change scenario planning in United States public land management agencies”) of its use in the U.S. National Park Service. Accuratel
Authors
Joel H. Reynolds, Brian W. Miller, Gregor W. Schuurman, Wylie A. Carr, Amy Symstad, John E. Gross, Amber N. Runyon

Nerodia clarkii (Saltmarsh Watersnake). Predation

Predators of Nerodia clarkii are suspected to include larger species of crabs, fish, wading birds, snakes, alligators, and crocodiles. To our knowledge, there have only been two published observations of predation on N. clarkii, including a predation attempt from a Callinectes sapidus (Blue Crab) in Mississippi, USA and a successful predation by a Grus americana (Whooping Crane) in Texas, USA. Her
Authors
Bryna L. Daykin, Sidney T. Godfrey, Michael Cherkiss, Gareth Blakemore, Frank J. Mazzotti

Characterizing vegetation and return periods in avalanche paths using lidar and aerial imagery

Snow avalanches are a hazard and ecological disturbance across mountain landscapes worldwide. Understanding how avalanche frequency affects forests and vegetation improves infrastructure planning, risk management, and avalanche forecasting. We implemented a novel approach using lidar, aerial imagery, and a random forest model to classify imagery-observed vegetation within avalanche paths in southe
Authors
Erich Peitzsch, Chelsea Martin-Mikle, Jordy Hendrikx, Karl W. Birkeland, Daniel B. Fagre

Updated three-dimensional temperature maps for the Great Basin, USA

As part of the periodic update of the geothermal energy assessments for the USA (e.g., last update by Williams and others, 2008), a new three-dimensional temperature map has been constructed for the Great Basin, USA. Williams and DeAngelo (2011) identified uncertainty in estimates of conductive heat flow near land surface as the largest contributor to uncertainty in previously published temperatur
Authors
Erick Burns, Jacob DeAngelo, Colin F. Williams

Sea turtle density surface models along the United States Atlantic coast

Spatially explicit estimates of marine species distribution and abundance are required to quantify potential impacts from human activities such as military training and testing, fisheries interactions, and offshore energy development. There are 4 protected species of sea turtle (loggerhead, green, Kemp’s ridley, and leatherback) commonly found along the east coast of the USA, our study area, and w
Authors
Andrew DiMatteo, Jason J. Roberts, D. Todd Jones-Farrand, Lance Garrison, Kristen Hart, Robert D. Kenney, William A. McLellan, Kate Lomac-MacNair, Debra Palka, Meghan E. Rickard, Kelsey E. Roberts, Ann M. Zoidis, L. Sparks