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Page 1433, results 35801 - 35825

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Significance of headwater streams and perennial springs in ecological monitoring in Shenandoah National Park
Craig D. Snyder, James R. Webb, John A. Young, Zane B. Johnson
2013, Open-File Report 2013-1178
Shenandoah National Park has been monitoring water chemistry and benthic macroinvertebrates in stream ecosystems since 1979. These monitoring efforts were designed to assess the status and trends in stream condition associated with atmospheric deposition (acid rain) and changes in forest health due to gypsy moth infestations. The primary objective of...
Relationships between the health of Alaska Native communities and our environment -- phase 1, exploring and communicating
Durelle Smith
2013, Fact Sheet 2013-3066
Alaska Natives depend on local natural resources for nutritional and, for many, spiritual health. As a result, public health in Alaska is strongly influenced by the relationship between people and their surrounding physical, chemical, and biological environments. Alaska is vast with diverse wildlife and plant communities that are valued as...
Fine-scale hydrologic modeling for regional landscape applications: the California Basin Characterization Model development and performance
Lorraine E. Flint, Alan L. Flint, James H. Thorne, Ryan Boynton
2013, Ecological Processes (2) 1-21
IntroductionResource managers need spatially explicit models of hydrologic response to changes in key climatic drivers across variable landscape conditions. We demonstrate the utility of a Basin Characterization Model for California (CA-BCM) to integrate high-resolution data on physical watershed characteristics with historical or projected climate data to...
Possible return of Acropora cervicornis at Pulaski Shoal, Dry Tortugas National Park, Florida
Barbara H. Lidz, David G. Zawada
2013, Journal of Coastal Research (29) 256-271
Seabed classification is essential to assessing environmental associations and physical status in coral reef ecosystems. At Pulaski Shoal in Dry Tortugas National Park, Florida, nearly continuous underwater-image coverage was acquired in 15.5 hours in 2009 along 70.2 km of transect lines spanning ~0.2 km2. The Along-Track Reef-Imaging System (ATRIS), a...
Self-reporting bias in Chinook salmon sport fisheries in Idaho: implications for roving creel surveys
Joshua L. McCormick, Michael C. Quist, Daniel J. Schill
2013, North American Journal of Fisheries Management (33) 723-731
Self-reporting bias in sport fisheries of Chinook Salmon Oncorhynchus tshawytscha in Idaho was quantified by comparing observed and angler-reported data. A total of 164 observed anglers fished for 541 h and caught 74 Chinook Salmon. Fifty-eight fish were harvested and 16 were released. Anglers reported fishing for 604 h, an...
Emerging methods for the study of coastal ecosystem landscape structure and change
John Brock, Jeffrey J. Danielson, Sam Purkis
2013, International Journal of Remote Sensing (34) 6283-6285
Coastal landscapes are heterogeneous, dynamic, and evolve over a range of time scales due to intertwined climatic, geologic, hydrologic, biologic, and meteorological processes, and are also heavily impacted by human development, commercial activities, and resource extraction. A diversity of complex coastal systems around the globe, spanning glaciated shorelines to tropical...
Naturally occurring contaminants in the Piedmont and Blue Ridge crystalline-rock aquifers and Piedmont Early Mesozoic basin siliciclastic-rock aquifers, eastern United States, 1994–2008
Melinda J. Chapman, Charles A. Cravotta III,, Zoltan Szabo, Bruce D. Lindsay
2013, Scientific Investigations Report 2013-5072
Groundwater quality and aquifer lithologies in the Piedmont and Blue Ridge Physiographic Provinces in the eastern United States vary widely as a result of complex geologic history. Bedrock composition (mineralogy) and geochemical conditions in the aquifer directly affect the occurrence (presence in rock and groundwater) and distribution (concentration and mobility)...
A new dry hypothesis for the formation of Martian linear gullies
Serina Diniega, Candice J. Hansen, Jim N. McElwaine, C.H. Hugenholtz, Colin M. Dundas, Alfred S. McEwen, Mary C. Bourke
2013, Icarus (225) 526-537
Long, narrow grooves found on the slopes of martian sand dunes have been cited as evidence of liquid water via the hypothesis that melt-water initiated debris flows eroded channels and deposited lateral levées. However, this theory has several short-comings for explaining the observed morphology and activity of these linear gullies....
Multi-scale habitat selection of the endangered Hawaiian Goose
Christina R. Leopold, Steven C. Hess
2013, Condor (115) 17-27
After a severe population reduction during the mid-20th century, the endangered Hawaiian Goose (Branta sandvicensis), or Nēnē, has only recently re-established its seasonal movement patterns on Hawai‘i Island. Little is currently understood about its movements and habitat use during the nonbreeding season. The objectives of this research were to identify...
Age structure of moose (Alces alces) killed by gray wolves (Canis lupus) in northeastern Minnesota, 1967-2011
L. David Mech, Michael E. Nelson
2013, Canadian Field-Naturalist (127) 70-71
The ages of 77 adult Moose (Alces alces) killed by Gray Wolves (Canis lupus) during the period 1967–2011 in northeastern Minnesota were significantly older than those of a sample of 17,585 Moose killed by hunters in nearby Ontario. Our findings support those of earlier studies of protected Moose populations in...
Variations of iron flux and organic carbon remineralization in a subterranean estuary caused by interannual variations in recharge
Moutusi Roy, Jonathan B. Martin, Jaye E. Cable, Christopher G. Smith
2013, Geochimica et Cosmochimica Acta (103) 301-315
We determine the inter-annual variations in diagenetic reaction rates of sedimentary iron (Fe ) in an east Florida subterranean estuary and evaluate the connection between metal fluxes and recharge to the coastal aquifer. Over the three-year study period (from 2004 to 2007), the amount of Fe-oxides reduced at the...
Methods for monitoring corals and crustose coralline algae to quantify in-situ calcification rates
Jennifer M. Morrison, Ilsa B. Kuffner, T. Don Hickey
2013, Open-File Report 2013-1159
The potential effect of global climate change on calcifying marine organisms, such as scleractinian (reef-building) corals, is becoming increasingly evident. Understanding the process of coral calcification and establishing baseline calcification rates are necessary to detect future changes in growth resulting from climate change or other stressors. Here we describe the...
Species- and community-level responses combine to drive phenology of lake phytoplankton
Annika Walters, Maria de los Angeles Gonzalez Sagrario, Daniel E. Schindler
2013, Ecology (94) 2188-2194
Global change is leading to shifts in the seasonal timing of growth and maturation for primary producers. Remote sensing is increasingly used to measure the timing of primary production in both aquatic and terrestrial ecosystems, but there is often a poor correlation between these results and direct observations of life-history...
Predicting the planform configuration of the braided Toklat River, AK with a suite of rule-based models
Charles J. Podolak
2013, Journal of the American Water Resources Association (49) 390-401
An ensemble of rule-based models was constructed to assess possible future braided river planform configurations for the Toklat River in Denali National Park and Preserve, Alaska. This approach combined an analysis of large-scale influences on stability with several reduced-complexity models to produce the predictions at a practical level for managers...
Distribution and exploitation of Nile perch Lates niloticus in relation to stratification in Lake Victoria, East Africa
A. Taabu-Munyaho, Robert J. Kayanda, Inigo Everson, Timothy B. Grabowski, Gudrun Marteinsdottir
2013, Journal of Great Lakes Research (39) 466-475
Stratification restricts habitable areas forcing fish to balance between favourable temperature and minimum dissolved oxygen requirements. Acoustic surveys conducted during the stratified and isothermal periods on tropical Lake Victoria indicated that stratification of temperature and dissolved oxygen (DO) affected vertical distribution of Nile perch. There was higher mean temperature (25.6...
Environmental and physical controls on northern terrestrial methane emissions across permafrost zones
David Olefeldt, Merritt R. Turetsky, Patrick M. Crill, A. David McGuire
2013, Global Change Biology (19) 589-603
Methane (CH4) emissions from the northern high-latitude region represent potentially significant biogeochemical feedbacks to the climate system. We compiled a database of growing-season CH4 emissions from terrestrial ecosystems located across permafrost zones, including 303 sites described in 65 studies. Data on environmental and physical variables, including permafrost conditions, were used...
Pre- and post-impoundment nitrogen in the lower Missouri River
Dale W. Blevins, Donald H. Wilkison, Shelley L. Niesen
2013, Hydrological Processes (28) 2535-2549
Large water-sample sets collected from 1899 through 1902, 1907, and in the early 1950s allow comparisons of pre-impoundment and post-impoundment (1969 through 2008) nitrogen concentrations in the lower Missouri River. Although urban wastes were not large enough to detectably increase annual loads of total nitrogen at the beginning of the...
Power to detect trends in abundance of secretive marsh birds: effects of species traits and sampling effort
Robert J. Steidl, Courtney J. Conway, Andrea R. Litt
2013, Journal of Wildlife Management (77) 445-453
Standardized protocols for surveying secretive marsh birds have been implemented across North America, but the efficacy of surveys to detect population trends has not been evaluated. We used survey data collected from populations of marsh birds across North America and simulations to explore how characteristics of bird populations (proportion of...
Permafrost thaw in a nested groundwater-flow system
Jeffery M. McKenzie, Clifford I. Voss
2013, Hydrogeology Journal (21) 299-316
Groundwater flow in cold regions containing permafrost accelerates climate-warming-driven thaw and changes thaw patterns. Simulation analyses of groundwater flow and heat transport with freeze/thaw in typical cold-regions terrain with nested flow indicate that early thaw rate is particularly enhanced by flow, the time when adverse environmental impacts of climate-warming-induced permafrost...
A twenty-first century California observing network for monitoring extreme weather events
A.B. White, M.L. Anderson, M. D. Dettinger, F.M. Ralph, A. Hinojosa, D.R. Cayan, R.K. Hartman, D.W. Reynolds, L.E. Johnson, T.L. Schneider, R. Cifelli, Z. Toth, S.I. Gutman, C.W. King, F. Gehrke, P.E. Johnston, C. Walls, Dorte Mann, D.J. Gottas, T. Coleman
2013, Journal of Atmospheric and Oceanic Technology (30) 1585-1603
During Northern Hemisphere winters, the West Coast of North America is battered by extratropical storms. The impact of these storms is of paramount concern to California, where aging water supply and flood protection infrastructures are challenged by increased standards for urban flood protection, an unusually variable weather regime, and projections...
On the conversion of tritium units to mass fractions for hydrologic applications
David A. Stonestrom, Brian J. Andraski, Clay A. Cooper, Charles J. Mayers, Robert L. Michel
2013, Isotopes in Environmental and Health Studies (49) 250-256
We develop a general equation for converting laboratory-reported tritium levels, expressed either as concentrations (tritium isotope number fractions) or mass-based specific activities, to mass fractions in aqueous systems. Assuming that all tritium is in the form of monotritiated water simplifies the derivation and is shown to be reasonable for most...
Observed impacts of duration and seasonality of atmospheric-river landfalls on soil moisture and runoff in coastal northern California
F.M. Ralph, T. Coleman, P.J. Neiman, R.J. Zamora, Mike Dettinger
2013, Journal of Hydrometeorology (14) 443-459
This study is motivated by diverse needs for better forecasts of extreme precipitation and floods. It is enabled by unique hourly observations collected over six years near California’s Russian River and by recent advances in the science of atmospheric rivers (ARs). This study fills key gaps limiting the prediction of...
Estimating occupancy and predicting numbers of gray wolf packs in Montana using hunter surveys
Lindsey N. Rich, Robin E. Russell, Elizabeth M. Glenn, Michael S. Mitchell, Justin A. Gude, Kevin M. Podruzny, Carolyn A. Sime, Kent Laudon, David E. Ausband, James D. Nichols
2013, Journal of Wildlife Management (77) 1280-1289
Reliable knowledge of the status and trend of carnivore populations is critical to their conservation and management. Methods for monitoring carnivores, however, are challenging to conduct across large spatial scales. In the Northern Rocky Mountains, wildlife managers need a time- and cost-efficient method for monitoring gray wolf (Canis lupus) populations....
Water supply, demand, and quality indicators for assessing the spatial distribution of water resource vulnerability in the Columbia River Basin
Heejun Chang, Il-Won Jung, Angela L. Strecker, Daniel Wise, Martin Lafrenz, Vivek Shandas, Moradkhani, Alan Yeakley, Yangdong Pan, Gunnar Johnson, Mike Psaris
2013, Atmosphere - Ocean (51) 339-356
We investigated water resource vulnerability in the US portion of the Columbia River basin (CRB) using multiple indicators representing water supply, water demand, and water quality. Based on the US county scale, spatial analysis was conducted using various biophysical and socio-economic indicators that control water vulnerability. Water supply vulnerability and...
Geologic map of the Valley Mountain 15’ quadrangle, San Bernardino and Riverside Counties, California
Keith A. Howard, John Bacheller, Todd T. Fitzgibbon, Robert E. Powell, Charlotte M. Allen
2013, Geologic Quadrangle 1767
The Valley Mountain 15’ quadrangle straddles the Pinto Mountain Fault, which bounds the eastern Transverse Ranges in the south against the Mojave Desert province in the north. The Pinto Mountains, part of the eastern Transverse Ranges in the south part of the quadrangle expose a series of Paleoproterozoic gneisses and...