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: 1226
A simple solar radiation index for wildlife habitat studies
Solar radiation is a potentially important covariate in many wildlife habitat studies, but it is typically addressed only indirectly, using problematic surrogates like aspect or hillshade. We devised a simple solar radiation index (SRI) that combines readily available information about aspect, slope, and latitude. Our SRI is proportional to the amount of extraterrestrial solar radiation theoretica
Authors
Kim A. Keating, Peter J. Gogan, John N. Vore, Lynn R. Irby
The art and science of weed mapping
Land managers need cost-effective and informative tools for non-native plant species management. Many local, state, and federal agencies adopted mapping systems designed to collect comparable data for the early detection and monitoring of non-native species. We compared mapping information to statistically rigorous, plot-based methods to better understand the benefits and compatibility of the two
Authors
David T. Barnett, Thomas J. Stohlgren, Catherine S. Jarnevich, Geneva W. Chong, Jenny A. Ericson, Tracy R. Davern, Sara E. Simonson
Evaluating estimators for numbers of females with cubs-of-the-year in the Yellowstone grizzly bear population
Current management of the grizzly bear (Ursus arctos) population in Yellowstone National Park and surrounding areas requires annual estimation of the number of adult female bears with cubs-of-the-year. We examined the performance of nine estimators of population size via simulation. Data were simulated using two methods for different combinations of population size, sample size, and coefficient of
Authors
S. Cherry, G.C. White, K.A. Keating, Mark A. Haroldson, Charles C. Schwartz
Spatial population structure of Yellowstone bison
Increases in Yellowstone National Park, USA, bison (Bison bison) numbers and shifts in seasonal distribution have resulted in more frequent movements of bison beyond park boundaries and development of an interagency management plan for the Yellowstone bison population. Implementation of the plan under the adaptive management paradigm requires an understanding of the spatial and temporal structure
Authors
Edward M. Olexa, Peter J. Gogan
Identifying sites for elk restoration in Arkansas
We used spatial data to identify potential areas for elk (Cervus elaphus) restoration in Arkansas. To assess habitat, we used locations of 239 elk groups collected from helicopter surveys in the Buffalo National River area of northwestern Arkansas, USA, from 1992 to 2002. We calculated the Mahalanobis distance (D2) statistic based on the relationship between those elk-group locations and a suite o
Authors
R.L. Telesco, F.T. Van Manen, J. D. Clark, Michael E. Cartwright
Alpine ecosystem dynamics and change: A view from the heights
No abstract available.
Authors
G.P. Malanson, D.R. Butler, Daniel B. Fagre
Modeling and monitoring biophysical dynamics and change
No abstract available.
Authors
Daniel B. Fagre
Response of western mountain ecosystems to climatic variability and change: The Western Mountain Initiative
Mountain ecosystems within our national parks and other protected areas provide valuable goods and services such as clean water, biodiversity conservation, and recreational opportunities, but their potential responses to expected climatic changes are inadequately understood. The Western Mountain Initiative (WMI) is a collaboration of scientists whose research focuses on understanding and predictin
Authors
Nathan L. Stephenson, David A. Peterson, Daniel B. Fagre, Craig D. Allen, Donald McKenzie, Jill Baron, K. O'Brien
Uncertainty management, spatial and temporal reasoning, and validation of intelligent environmental decision support systems
There are inherent open problems arising when developing and running Intelligent Environmental
Decision Support Systems (IEDSS). During daily operation of IEDSS several open challenge problems
appear. The uncertainty of data being processed is intrinsic to the environmental system, which is being
monitored by several on-line sensors and off-line data. Thus, anomalous data values at data gatheri
Authors
Miquel Sànchez-Marrè, Karina Gilbert, Rick S. Sojda, Jean Philippe Steyer, Peter Struss, Ignasi Rodríguez-Roda
Ecological and sampling constraints on defining landscape fire severity
Ecological definition and detection of fire severity are influenced by factors of spatial resolution and timing. Resolution determines the aggregation of effects within a sampling unit or pixel (alpha variation), hence limiting the discernible ecological responses, and controlling the spatial patchiness of responses distributed throughout a burn (beta variation). As resolution decreases, alpha var
Authors
C.H. Key
Grizzly bear management in Yellowstone National Park: The heart of recovery in the Yellowstone Ecosystem
Grizzly bear (Ursus arctos) management in the Greater Yellowstone Ecosystem (GYE) in the past quarter century has resulted in more than doubling of the population from around 200 to more than 500, expansion of range back into habitats where the bear has extirpated more than a century ago, and a move toward removal from the U.S. Endangered Species list. At the center of this success story are the m
Authors
C.C. Schwartz, K. Gunther