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: 1216
Use of a wetland index to evaluate changes in riparian vegetation after livestock exclusion
A method was developed to characterize ecological integrity of riparian sites based on the abundance of hydric species. This wetland index can be calculated with species data, or with community type data as performed here. Classified riparian community types were used to describe vegetation at 14 livestock exclosures and adjacent grazed areas. Community type wetland index values were generated and
Authors
M. C. Coles-Ritchie, D.W. Roberts, J. L. Kershner, R.C. Henderson
The impact of time and field conditions on brown bear (Ursus arctos) faecal DNA amplification
To establish longevity of faecal DNA samples under varying summer field conditions, we collected 53 faeces from captive brown bears (Ursus arctos) on a restricted vegetation diet. Each faeces was divided, and one half was placed on a warm, dry field site while the other half was placed on a cool, wet field site on Moscow Mountain, Idaho, USA. Temperature, relative humidity, and dew point data were
Authors
M.A. Murphy, K.C. Kendall, A. Robinson, L.P. Waits
Testing a Mahalanobis distance model of black bear habitat use in the Ouachita Mountains of Oklahoma
Regional wildlife–habitat models are commonly developed but rarely tested with truly independent data. We tested a published habitat model for black bears (Ursus americanus) with new data collected in a different site in the same ecological region (i.e., Ouachita Mountains of Arkansas and Oklahoma, USA). We used a Mahalanobis distance model developed from relocations of black bears in Arkansas to
Authors
E. C. Hellgren, S.L. Bales, M.S. Gregory, David M. Leslie, J. D. Clark
Population-scale movement of coastal cutthroat trout in a naturally isolated stream network
To identify population‐scale patterns of movement, coastal cutthroat trout Oncorhynchus clarkii clarkii tagged and marked (35 radio‐tagged, 749 passive integrated transponder [PIT]‐tagged, and 3,025 fin‐clipped) were monitored from June 1999 to August 2000. The study watershed, located in western Oregon, was above a natural barrier to upstream movement. Emigration out of the watershed was estimate
Authors
R. E. Gresswell, S.R. Hendricks
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, Dave Peterson, Daniel B. Fagre, Craig D. Allen, Donald McKenzie, Jill Baron, Kelly O'Brian
Sequence analysis of the msp4 gene of Anaplasma ovis strains
Anaplasma ovis (Rickettsiales: Anaplasmataceae) is a tick-borne pathogen of sheep, goats and wild ruminants. The genetic diversity of A. ovis strains has not been well characterized due to the lack of sequence information. In this study, we evaluated bighorn sheep (Ovis canadensis) and mule deer (Odocoileus hemionus) from Montana for infection with A. ovis by serology and sequence analysis of the
Authors
J. de la Fuente, M.W. Atkinson, V. Naranjo, I. G. Fernandez de Mera, A.J. Mangold, K.A. Keating, K. M. Kocan
Rapid assessment of postfire plant invasions in coniferous forests of the western United States
Fire is a natural part of most forest ecosystems in the western United States, but its effects on nonnative plant invasion have only recently been studied. Also, forest managers are engaging in fuel reduction projects to lessen fire severity, often without considering potential negative ecological consequences such as nonnative plant species introductions. Increased availability of light, nutrient
Authors
J.P. Freeman, T.J. Stohlgren, M.E. Hunter, Philip N. Omi, E.J. Martinson, G.W. Chong, C. S. Brown
Development of a spatial analysis method using ground-based repeat photography to detect changes in the alpine treeline ecotone, Glacier National Park, Montana, U.S.A.
Repeat photography is a powerful tool for detection of landscape change over decadal timescales. Here a novel method is presented that applies spatial analysis software to digital photo-pairs, allowing vegetation change to be categorized and quantified. This method is applied to 12 sites within the alpine treeline ecotone of Glacier National Park, Montana, and is used to examine vegetation changes
Authors
W. Roush, Jeffrey S. Munroe, D.B. Fagre
Return to the wild: Translocation as a tool in conservation of the desert tortoise (Gopherus agassizii)
Translocation could be used as a tool in conservation of the threatened Mojave Desert Tortoise (Gopherus agassizii) by moving individuals from harm's way and into areas where they could contribute to conservation of the species. Numerous factors may affect the success of translocations, including the conditions experienced by tortoises in holding facilities while awaiting translocation. The tortoi
Authors
K.J. Field, C.R. Tracy, P.A. Medica, R.W. Marlow, P. S. Corn
Use of seasonal freshwater wetlands by fishes in a temperate river floodplain
This study examined the use of freshwater wetland restoration and enhancement projects (i.e. non-estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement (i.e. addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two oxbow habita
Authors
Julie A. Henning, Robert E. Gresswell, Ian A. Fleming
Empirical evaluation of decision support systems: Needs, definitions, potential methods, and an example pertaining to waterfowl management
Decision support systems are often not empirically evaluated, especially the underlying modelling components. This can be attributed to such systems necessarily being designed to handle complex and poorly structured problems and decision making. Nonetheless, evaluation is critical and should be focused on empirical testing whenever possible. Verification and validation, in combination, comprise su
Authors
R.S. Sojda
Amphibians and disease: Implications for conservation in the Greater Yellowstone Ecosystem
The decline of amphibian populations is a world-wide phenomenon that has received increasing attention since about 1990. In 2004, the World Conservation Union’s global amphibian assessment concluded that 48% of the world’s 5,743 described amphibian species were in decline, with 32% considered threatened (Stuart et al. 2004). Amphibian declines are a significant issue in the western United States,
Authors
Paul Stephen Corn