Publications
Below is a list of available NOROCK peer reviewed and published science. If you are in search of a specific publication and cannot find it below or through a search, please contact twojtowicz@usgs.gov.
Filter Total Items: 1252
A hierarchical model for eDNA fate and transport dynamics accommodating low concentration samples
Environmental DNA (eDNA) sampling is an increasingly important tool for answering ecological questions and informing aquatic species management; however, several factors currently limit the reliability of ecological inference from eDNA sampling. Two particular challenges are (1) determining species source location(s) and (2) accurately and precisely measuring low concentration eDNA...
Authors
Ben Augustine, Patrick R. Hutchins, Devin Nicole Jones, Jacob R. Williams, Eric Leinonen, Adam Sepulveda
Assessing predictions from optimal egg theory for an ectotherm relative to habitat duration
Optimal egg size theory predicts females must balance investment per offspring to maximize fitness based on environmental quality. In wetlands, environmental quality can be duration of water and predator presence. Ectotherms using habitats that dry or contain predators are likely under selection to optimize offspring production. We measured reproductive output of wood frogs (Rana...
Authors
Jon D Davenport, Andrew Feltmann, LeeAnn Fishback, Blake Hossack
GNSS reflectometry from low-cost sensors for continuous in situ contemporaneous glacier mass balance and flux divergence
Recent advances in remote sensing have produced global glacier surface elevation change data. Parsing these elevation change signals into contributions from the climate (i.e. climatic mass balance) and glacier dynamics (i.e. flux divergence) is critical to enhance our process-based understanding of glacier change. In this study, we evaluate three approaches for direct, continuous...
Authors
Albin Wells, David R. Rounce, Louis Sass, Caitlyn Florentine, Adam Garbo, Emily Baker, Christopher Mcneil
Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, Alaska
Knowledge of snow and firn-density change is needed to use elevation-change measurements to estimate glacier mass change. Additionally, firn-density evolution on glaciers is closely connected to meltwater percolation, refreezing and runoff, which are key processes for glacier mass balance and hydrology. Since 2016, the U.S. Geological Survey Benchmark Glacier Project has recovered firn...
Authors
Max Stevens, Louis Sass, Caitlyn Florentine, Christopher Mcneil, Emily Baker, Katherine Eleanore Bollen
Demographic risk factors vary in the invasion front of chronic wasting disease in West Virginia, USA
After detecting chronic wasting disease (CWD) in white-tailed deer (Odocoileus virginianus) in Hampshire County, West Virginia, USA, in 2005, we investigated the change of CWD apparent prevalence and potential factors influencing infection risk during the invasion front. Over eight sampling years (2006–2012 and 2017) during a 12-yr period within a 101-km2-area monitoring zone, we sampled...
Authors
Brian Scott Dugovich, Ethan P. Barton, James M. Crum, M. Kevin Keel, David E. Stallknecht, Mark G. Ruder
Structured science syntheses to inform decision making on Federal public lands
The U.S. Geological Survey, Bureau of Land Management, and U.S. Fish and Wildlife Service partnered to develop a new type of science product: the structured science synthesis. Structured science syntheses are peer-reviewed reports that synthesize science information about a priority resource management issue on public lands. Structured science syntheses are developed explicitly to...
Authors
Emma I. Dietrich, Sarah K. Carter, Tait K. Rutherford, Megan A. Gilbert, Travis S. Haby, Aaron N. Johnston, Samuel E. Jordan, Nathan J. Kleist, Richard J. Lehrter, Elroy H. Masters, Claudia Mengelt, Alexandra L. Stoneburner, Elisabeth C. Teige, John C. Tull, Sarah E. Whipple, David J. A. Wood
Trends in plant cover derived from vegetation plot data using ordinal zero-augmented beta regression
QuestionsPlant cover values in vegetation plot data are bounded between 0 and 1, and cover is typically recorded in discrete classes with non-equal intervals. Consequently, cover data are skewed and heteroskedastic, which hampers the application of conventional regression methods. Recently developed ordinal beta regression models consider these statistical difficulties. Our primary...
Authors
Arco van Strien, Kathryn M. Irvine, Cas Retel
Glaciers and ice caps outside Greenland
No abstract available.
Authors
D. Burgess, G. Wolken, B. Wouters, L.M. Andreassen, Caitlyn Florentine, J. Kohler, B. Luks, F. Pálsson, Louis Sass, L. Thomson, T. Thorsteinsson
A unified approach to long-term population monitoring of grizzly bears in the Greater Yellowstone Ecosystem
Long-term wildlife research and monitoring programs strive to maintain consistent data collections and analytical methods. Incorporating new techniques is important but can render data sets incongruent and limit their potential to discern trends in demographic parameters. Integrated population models (IPMs) can address these limitations by combining data sources that may span different...
Authors
Matthew J. Gould, Justin Clapp, Mark A. Haroldson, Cecily M. Costello, J. Joshua Nowak, Hans Martin, Michael R. Ebinger, Daniel D. Bjornlie, Daniel P. Thompson, Justin A. Dellinger, Matthew A. Mumma, Paul M. Lukacs, Frank T. van Manen
Observing glacier elevation changes from spaceborne optical and radar sensors – an inter-comparison experiment using ASTER and TanDEM-X data
Observations of glacier mass changes are key to understanding the response of glaciers to climate change and related impacts, such as regional runoff, ecosystem changes, and global sea level rise. Spaceborne optical and radar sensors make it possible to quantify glacier elevation changes, and thus multi-annual mass changes, on a regional and global scale. However, estimates from a...
Authors
Livia Piermattei, Michael Zemp, Christian Sommer, Fanny Brun, Matthias H. Braun, Liss M. Andreassen, Joaquín M. C. Belart, Etienne Berthier, Atanu Bhattacharya, Laura Boehm Vock, Tobias Bolch, Amaury Dehecq, Inés Dussaillant, Daniel Falaschi, Caitlyn Florentine, Dana Floricioiu, Christian Ginzler, Gregoire Guillet, Romain Hugonnet, Andreas Kääb, Owen King, Christoph Klug, Friedrich Knuth, Lukas Krieger, Jeff La Frenierre, Robert McNabb, Christopher Mcneil, Rainer Prinz, Louis Sass, Thorsten Seehaus, David Shean, Désirée Treichler, Anja Wendt, Ruitang Yang
Wildland fire effects on sediment, salinity, and selenium yields in a basin underlain by Cretaceous marine shales near Rangely, Colorado
Understanding and quantifying soil erosion from rangelands is a high priority for land managers, especially in areas underlain by Cretaceous Mancos Shale, which is a natural source of sediment, salinity, and selenium to surface waters in many areas of western Colorado and eastern Utah. The purpose of this report is to present the results of a U.S. Geological Survey study that assessed...
Authors
Natalie K. Day, Todd M. Preston, Patrick C. Longley
Clustering and unconstrained ordination with Dirichlet process mixture models
Assessment of similarity in species composition or abundance across sampled locations is a common goal in multi-species monitoring programs. Existing ordination techniques provide a framework for clustering sample locations based on species composition by projecting high-dimensional community data into a low-dimensional, latent ecological gradient representing species composition...
Authors
Christian Stratton, Andrew B. Hoegh, Tom J Rodhouse, Jennifer L. Green, Katharine M. Banner, Kathryn M. Irvine