Luminescence ages for alluvial-fan deposits in Southern Death Valley: Implications for climate-driven sedimentation along a tectonically active mountain front
M.F. Sohn, S. A. Mahan, J.R. Knott, D.D. Bowman
2007, Quaternary International (166) 49-60
Controversy exists over whether alluvial-fan sedimentation along tectonically active mountain fronts is driven by climatic changes or tectonics. Knowing the age of sedimentation is the key to understanding the relationship between sedimentation and its cause. Alluvial-fan deposits in Death Valley and throughout the arid southwestern United States have long been...
Thermal criteria for early life stage development of the winged mapleleaf mussel (Quadrilla fragosa)
M.T. Steingraeber, M.R. Bartsch, J.E. Kalas, T.J. Newton
2007, American Midland Naturalist (157) 297-311
The winged mapleleaf mussel [Quadrula fragosa (Conrad)] is a Federal endangered species. Controlled propagation to aid in recovering this species has been delayed because host fishes for its parasitic glochidia (larvae) are unknown. This study identified blue catfish [Ictaluris furcatus (Lesueur)] and confirmed channel catfish [Ictaluris punctatus (Rafinesque)] as suitable...
Hydrology and water quality in two mountain basins of the northeastern US: Assessing baseline conditions and effects of ski area development
B. Wemple, J. Shanley, J. Denner, D. Ross, K. Mills
2007, Conference Paper, Hydrological Processes
Mountain regions throughout the world face intense development pressures associated with recreational and tourism uses. Despite these pressures, much of the research on bio-geophysical impacts of humans in mountain regions has focused on the effects of natural resource extraction. This paper describes findings from the first 3 years of a...
A field assessment of the value of steady shape hydraulic tomography for characterization of aquifer heterogeneities
Geoffrey C. Bohling, James J. Butler Jr., Xiaoyong Zhan, Michael D. Knoll
2007, Water Resources Research (43)
Hydraulic tomography is a promising approach for obtaining information on variations in hydraulic conductivity on the scale of relevance for contaminant transport investigations. This approach involves performing a series of pumping tests in a format similar to tomography. We present a field‐scale assessment of hydraulic tomography in a porous aquifer,...
Molecular analysis of fungal communities and laccase genes in decomposing litter reveals differences among forest types but no impact of nitrogen deposition
C.B. Blackwood, M. P. Waldrop, D.R. Zak, R. L. Sinsabaugh
2007, Environmental Microbiology (9) 1306-1316
The fungal community of the forest floor was examined as the cause of previously reported increases in soil organic matter due to experimental N deposition in ecosystems producing predominantly high-lignin litter, and the opposite response in ecosystems producing low-lignin litter. The mechanism proposed to explain this phenomenon was that white-rot...
Current-use pesticides and organochlorine compounds in precipitation and lake sediment from two high-elevation national parks in the Western United States
M.A. Mast, W.T. Foreman, S.V. Skaates
2007, Archives of Environmental Contamination and Toxicology (52) 294-305
Current-use pesticides (CUPs) and banned organochlorine compounds (OCCs) were measured in precipitation (snowpack and rain) and lake sediments from two national parks in the Western United States to determine their occurrence and distribution in high-elevation environments. CUPs frequently detected in snow were endosulfan, dacthal, and chlorothalonil in concentrations ranging from...
Occurrence of the amphibian pathogen Batrachochytrium dendrobatidis in Pacific Northwestern USA
Christopher A. Pearl, E. L. Bull, D. E. Green, Jay Bowerman, M. J. Adams, A. Hyatt, W. Wente
2007, Journal of Herpetology (41) 145-149
Chytridiomycosis (infection by the fungus Batrachochytrium dendrobatidis) has been associated with amphibian declines in at least four continents. We report results of disease screens from 210 pond-breeding amphibians from 37 field sites in Oregon and Washington. We detected B. dendrobatidis on 28% of sampled amphibians, and and we found ->...
Grids of Agricultural Pesticide Use in the Conterminous United States, 1992
Naomi Nakagaki
2007, Report
This spatial dataset consists of 199 1-kilometer (km) resolution grids depicting estimated agricultural use of 199 pesticides in 1992 for the conterminous United States. Each grid cell value in the national grids of this dataset is the estimated total kilograms (kg) of a pesticide applied to row crops, small grain...
The Northern end of the Dead Sea Basin: Geometry from reflection seismic evidence
A. S. Al-Zoubi, T. Heinrichs, I. Qabbani, Uri S. ten Brink
2007, Tectonophysics (434) 55-69
Recently released reflection seismic lines from the Eastern side of the Jordan River north of the Dead Sea were interpreted by using borehole data and incorporated with the previously published seismic lines of the eastern side of the Jordan River. For the first time, the lines from the eastern side...
Grids of agricultural pesticide use in the conterminous United States, 1997
Naomi Nakagaki
2007, Report
This spatial dataset consists of 219 1-kilometer (km) resolution grids depicting estimated agricultural use of 219 pesticides in 1997 for the conterminous United States. Each grid cell value in the national grids of this dataset is the estimated total kilograms (kg) of a pesticide applied to row crops, small grain...
Nitrate retention in riparian ground water at natural and elevated nitrate levels in North Central Minnesota
J.H. Duff, A. P. Jackman, F.J. Triska, R.W. Sheibley, R.J. Avanzino
2007, Journal of Environmental Quality (36) 343-353
The relationship between local ground water flows and NO3− transport to the channel was examined in three well transects from a natural, wooded riparian zone adjacent to the Shingobee River, MN. The hillslope ground water originated as recharge from intermittently grazed pasture up slope of the site. In the hillslope...
Three distinct clades of cultured heterocystous cyanobacteria constitute the dominant N2-fixing members of biological soil crusts of the Colorado Plateau, USA
C.M. Yeager, J. L. Kornosky, R.E. Morgan, E.C. Cain, F. Garcia-Pichel, D.C. Housman, J. Belnap, C.R. Kuske
2007, FEMS Microbiology Ecology (60) 85-97
The identity of the numerically dominant N2-fixing bacteria in biological soil crusts of the Colorado Plateau region and two outlying areas was determined using multiple approaches, to link the environmental diversity of nifH gene sequences to cultured bacterial isolates from the regions. Of the nifH sequence-types detected in soil crusts...
Alaskan birds at risk: Widespread beak deformities in resident species
Caroline R. Van Hemert
2007, Birding (39) 48-55
The team creeps silently across a well-tended lawn, eyes drawn to a small wooden box perched several meters up a lone birch tree. The first biologist is armed with a broom in one hand and a bug net in the other. Her partner wields a lunchbox-sized plastic case and a...
Colored dissolved organic matter in Tampa Bay, Florida
Z. Chen, C. Hu, R.N. Conmy, F. Muller-Karger, P. Swarzenski
2007, Marine Chemistry (104) 98-109
Absorption and fluorescence of colored dissolved organic matter (CDOM) and concentrations of dissolved organic carbon (DOC), chlorophyll and total suspended solids in Tampa Bay and its adjacent rivers were examined in June and October of 2004. Except in Old Tampa Bay (OTB), the spatial distribution of CDOM showed a conservative...
The effects of acidic mine drainage from historical mines in the Animas River watershed, San Juan County, Colorado—What is being done and what can be done to improve water quality?
Stanley E. Church, Robert J. Owen, Paul Von Guerard, Philip L. Verplanck, Briant A. Kimball, Douglas B. Yager
2007, Book chapter, Understanding and responding to hazardous substances at mine sites in the western United States
Historical production of metals in the western United States has left a legacy of acidic drainage and toxic metals in many mountain watersheds that are a potential threat to human and ecosystem health. Studies of the effects of historical mining on surface water chemistry and riparian habitat in the Animas...
Mapping impervious surfaces using classification and regression tree algorithm
G. Xian
Q. Weng, editor(s)
2007, Book chapter, Remote sensing of impervious surfaces
No abstract available....
Oregon Spotted Frog (Rana pretiosa) movement and demography at Dilman Meadow: Implications for future monitoring
Nathan D. Chelgren, Christopher A. Pearl, Jay Bowerman, M. J. Adams
2007, Open-File Report 2007-1016
From 2001 to 2005, we studied the demography and seasonal movement of Oregon spotted frogs (Rana pretiosa) translocated into created ponds in Dilman Meadow in central Oregon. Our objectives were to inform future monitoring and management at the site, and to elucidate poorly known aspects of the species’ population ecology....
Nesting ecology of boreal forest birds following a massive outbreak of spruce beetles
Steven M. Matsuoka, Colleen M. Handel
2007, Journal of Wildlife Management (71) 51-63
We studied breeding dark-eyed juncos (Junco hyemalis), yellow-rumped warblers (Dendroica coronata), and spruce-nesting birds from 1997 to 1998 among forests with different levels of spruce (Picea spp.) mortality following an outbreak of spruce beetles (Dendroctonus rufipennis) in Alaska, USA. We identified species using live and beetle-killed spruce for nest sites and...
Survey trends of North American shorebirds: Population declines or shifting distributions?
Jonathan Bart, Stephen Brown, Brian A. Harrington, R.I. Guy Morrison
2007, Journal of Avian Biology (38) 73-82
We analyzed data from two surveys of fall migrating shorebirds in central and eastern North America to estimate annual trends in means per survey and to determine whether trends indicate a change in population size or might have been caused by other factors. The analysis showed a broad decline in...
Microplate model for the present-day deformation of Tibet
W. Thatcher
2007, Journal of Geophysical Research B: Solid Earth (112)
[1] Site velocities from 349 Global Positioning System (GPS) stations are used to construct an 11-element quasi-rigid block model of the Tibetan Plateau and its surroundings. Rigid rotations of five major blocks are well determined, and average translation velocities of six smaller blocks can be constrained....
Seasonal variation in nutrient retention during inundation of a short-hydroperiod floodplain
G.B. Noe, C.R. Hupp
2007, River Research and Applications (23) 1088-1101
Floodplains are generally considered to be important locations for nutrient retention or inorganic-to-organic nutrient conversions in riverine ecosystems. However, little is known about nutrient processing in short-hydroperiod floodplains or seasonal variation in floodplain nutrient retention. Therefore, we quantified the net uptake, release or transformation of nitrogen (N), phosphorus (P) and...
Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids
G.B. Lawrence, J.W. Sutherland, C.W. Boylen, S. W. Nierzwicki-Bauer, B. Momen, Barry P. Baldigo, H. A. Simonin
2007, Environmental Science & Technology (41) 93-98
Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is...
Toward a transport-based analysis of nutrient spiraling and uptake in streams
Robert L. Runkel
2007, Limnology and Oceanography: Methods (5) 50-62
Nutrient addition experiments are designed to study the cycling of nutrients in stream ecosystems where hydrologic and nonhydrologic processes determine nutrient fate. Because of the importance of hydrologic processes in stream ecosystems, a conceptual model known as nutrient spiraling is frequently employed. A central part of the nutrient spiraling approach...
Brown-headed cowbird, Molothrus ater, parasitism and abundance in the northern Great Plains
L.D. Igl, Douglas H. Johnson
2007, Canadian Field-Naturalist (121) 239-255
The Brown-headed Cowbird (Molothrus ater) reaches its highest abundance in the northern Great Plains, but much of our understanding of cowbird ecology and host-parasite interactions comes from areas outside of this region. We examine cowbird brood parasitism and densities during two studies of breeding birds in the northern Great Plains...
Exposure of unionid mussels to electric current: Assessing risks associated with electrofishing
F.M. Holliman, T.J. Kwak, W.G. Cope, Jay F. Levine
2007, Transactions of the American Fisheries Society (136) 1593-1606
Electric current is routinely applied in freshwater for scientific sampling of fish populations (i.e., electrofishing). Freshwater mussels (families Margaritiferidae and Unionidae) are distributed worldwide, but their recent declines in diversity and abundance constitute an imperilment of global significance. Freshwater mussels are not targeted for capture by electrofishing, and any exposure...
