Volcano dome dynamics at Mount St. Helens: Deformation and intermittent subsidence monitored by seismicity and camera imagery pixel offsets
Jacqueline T. Salzer, Weston A. Thelen, Mike R. James, Thomas R. Walter, Seth C. Moran, Roger P. Denlinger
2016, Journal of Geophysical Research B: Solid Earth (121) 7882-7902
The surface deformation field measured at volcanic domes provides insights into the effects of magmatic processes, gravity- and gas-driven processes, and the development and distribution of internal dome structures. Here we study short-term dome deformation associated with earthquakes at Mount St. Helens, recorded by a permanent optical camera and seismic...
Holocene volcanism of the upper McKenzie River catchment, central Oregon Cascades, USA
Natalia I. Deligne, Richard M. Conrey, Katharine V. Cashman, Duane E. Champion, William H. Amidon
2016, Geological Society of America Bulletin (128) 1618-1635
To assess the complexity of eruptive activity within mafic volcanic fields, we present a detailed geologic investigation of Holocene volcanism in the upper McKenzie River catchment in the central Oregon Cascades, United States. We focus on the Sand Mountain volcanic field, which covers 76 km2 and consists of 23 vents,...
Multiple browsers structure tree recruitment in logged temperate forests
Edward K. Faison, Stephen DeStefano, David R. Foster, Joshua M. Rapp, Justin A. Compton
2016, PLoS ONE (11) 1-14
Historical extirpations have resulted in depauperate large herbivore assemblages in many northern forests. In eastern North America, most forests are inhabited by a single wild ungulate species, white-tailed deer (Odocoileus virginianus), and relationships between deer densities and impacts on forest regeneration are correspondingly well documented. Recent recolonizations by moose (Alces...
Low-cost floating emergence net and bottle trap: Comparison of two designs
Pete Cadmus, Justin Pomeranz, Johanna M. Kraus
2016, Journal of Freshwater Ecology (31) 653-658
Sampling emergent aquatic insects is of interest to many freshwater ecologists. Many quantitative emergence traps require the use of aspiration for collection. However, aspiration is infeasible in studies with large amounts of replication that is often required in large biomonitoring projects. We designed an economic, collapsible pyramid-shaped floating emergence trap...
The precision problem in conservation and restoration
J. Kevin Hiers, Stephen T. Jackson, Richard J. Hobbs, Emily S. Bernhardt, Leonie E. Valentine
2016, Trends in Ecology and Evolution (31) 820-830
Within the varied contexts of environmental policy, conservation of imperilled species populations, and restoration of damaged habitats, an emphasis on idealized optimal conditions has led to increasingly specific targets for management. Overly-precise conservation targets can reduce habitat variability at multiple scales, with unintended consequences for future ecological resilience. We describe...
Space use of a dominant Arctic vertebrate: Effects of prey, sea ice, and land on Pacific walrus resource selection
William S. Beatty, Chadwick V. Jay, Anthony S. Fischbach, Jacqueline M. Grebmeier, Rebecca L. Taylor, Arny L. Blanchard, Stephen C. Jewett
2016, Biological Conservation (203) 25-32
Sea ice dominates marine ecosystems in the Arctic, and recent reductions in sea ice may alter food webs throughout the region. Sea ice loss may also stress Pacific walruses (Odobenus rosmarus divergens), which feed on benthic macroinvertebrates in the Bering and Chukchi seas. However, no studies have examined the effects...
A glacier runoff extension to the Precipitation Runoff Modeling System
Ashley E. Van Beusekom, Roland J. Viger
2016, Journal of Geophysical Research F: Earth Surface (121) 2001-2021
A module to simulate glacier runoff, PRMSglacier, was added to PRMS (Precipitation Runoff Modeling System), a distributed-parameter, physical-process hydrological simulation code. The extension does not require extensive on-glacier measurements or computational expense but still relies on physical principles over empirical relations as much as is feasible while maintaining model usability....
Landsat 8: The plans, the reality, and the legacy
Thomas R. Loveland, James R. Irons
2016, Remote Sensing of Environment (185) 1-6
Landsat 8, originally known as the Landsat Data Continuity Mission (LDCM), is a National Aeronautics and Space Administration (NASA)-U.S. Geological Survey (USGS) partnership that continues the legacy of continuous moderate resolution observations started in 1972. The conception of LDCM to the reality of Landsat 8 followed an arduous path extending...
The use of amino acid indices for assessing organic matter quality and microbial abundance in deep-sea Antarctic sediments of IODP Expedition 318
Stephanie A Carr, Christopher T. Mills, Kevin W Mandernack
2016, Marine Chemistry (186) 72-82
The Adélie Basin, located offshore of the Wilkes Land margin, experiences unusually high sedimentation rates (~ 2 cm yr− 1) for the Antarctic coast. This study sought to compare depthwise changes in organic matter (OM) quantity and quality with changes in microbial biomass with depth at this high-deposition site and an offshore continental margin...
Scale-dependent seasonal pool habitat use by sympatric Wild Brook Trout and Brown Trout populations
Lori A. Davis, Tyler Wagner
2016, Transactions of the American Fisheries Society (145) 888-902
Sympatric populations of native Brook Trout Salvelinus fontinalis and naturalized Brown Trout Salmo truttaexist throughout the eastern USA. An understanding of habitat use by sympatric populations is of importance for fisheries management agencies because of the close association between habitat and population dynamics. Moreover, habitat use by stream-dwelling salmonids may...
Land–atmosphere feedbacks amplify aridity increase over land under global warming
Alexis Berg, Kirsten Findell, Benjamin Lintner, Alessandra Giannini, Sonia I. Seneviratne, Bart van den Hurk, Ruth Lorenz, Andy Pitman, Stefan Hagemann, Arndt Meier, Frederique Cheruy, Agnes Ducharne, Sergey Malyshev, Paul C. D. Milly
2016, Nature Climate Change (6) 869-874
The response of the terrestrial water cycle to global warming is central to issues including water resources, agriculture and ecosystem health. Recent studies indicate that aridity, defined in terms of atmospheric supply (precipitation, P) and demand (potential evapotranspiration, Ep) of water at the land surface, will increase globally in a...
A brackish diatom, Pseudofrustulia lancea gen. et sp. nov. (Bacillariophyceae), from the Pacific coast of Oregon (USA)
Yuki Sawai, Tamotsu Nagumo, Alan R. Nelson
2016, Phytotaxa (267) 103-112
Light and electron microscope observations show that a brackish diatom taxon should be classified as a new species of a new genus; Pseudofrustulia lancea gen. et sp. nov. We propose separating Pseudofrustulia from other similar genera such as Frickea, Frustulia, Amphipleura, Muelleria, and Envekadea on the basis of its thickened...
Annual elk calf survival in a multiple carnivore system
Daniel R. Eacker, Mark Hebblewhite, Kelly M. Proffitt, Benjamin S. Jimenez, Michael S. Mitchell, Hugh S. Robinson
2016, Journal of Wildlife Management (80) 1345-1359
The realized effect of multiple carnivores on juvenile ungulate recruitment may depend on the carnivore assemblage as well as compensation from forage and winter weather severity, which may mediate juvenile vulnerability to predation in ungulates. We used a time-to-event approach to test for the effects of risk factors on annual...
Estimation of time-variable fast flow path chemical concentrations for application in tracer-based hydrograph separation analyses
Scott C. Kronholm, Paul D. Capel
2016, Water Resources Research (52) 6881-6896
Mixing models are a commonly used method for hydrograph separation, but can be hindered by the subjective choice of the end-member tracer concentrations. This work tests a new variant of mixing model that uses high-frequency measures of two tracers and streamflow to separate total streamflow into water from slowflow and...
Pb-Sr isotopic and geochemical constraints on sources and processes of lead contamination in well waters and soil from former fruit orchards, Pennsylvania, USA: A legacy of anthropogenic activities
Robert A. Ayuso, Nora K. Foley
2016, Journal of Geochemical Exploration (170) 125-147
Isotopic discrimination can be an effective tool in establishing a direct link between sources of Pb contamination and the presence of anomalously high concentrations of Pb in waters, soils, and organisms. Residential wells supplying water containing up to 1600 ppb Pb to houses built on the former Mohr orchards commercial site,...
Response of imperiled Okaloosa darters to stream restoration
David B. Reeves, William B. Tate, Howard L. Jelks, Frank Jordan
2016, North American Journal of Fisheries Management (36) 1375-1385
The Okaloosa Darter Etheostoma okaloosae is a small percid endemic to six stream drainages in northwestern Florida. The U.S. Fish and Wildlife Service listed Okaloosa Darters as endangered in 1973 and downlisted them to threatened in 2011 because of habitat improvements and increasing abundance across much of their geographic range....
Comment on “Reconciliation of the Devils Hole climate record with orbital forcing”
Tyler B. Coplen
2016, Science (354) 296-296
Moseley et al.’s (Reports, 8 January 2016, p. 165) preferred-Termination-II age is subjective, as evidenced by variation in their Termination-II ages of 2500 years per meter. Termination-II-age bias decreases to zero at ~1.5 meters below the present-day water table, if one assumes linear variation with core-sample height. Maintaining the required...
New findings of twisted-wing parasites (Strepsiptera) in Alaska
Molly Mcdermott
2016, Newsletter of the Alaska Entomological Society (9) 6-8
Strepsipterans are a group of insects with a gruesome life history and an enigmatic evolutionary past. Called ‘twisted-wing parasites’, they are minute parasitoids with a very distinct morphology (Figure 1). Alternatively thought to be related to ichneumon wasps, Diptera (flies), Coleoptera (beetles), and even Neuroptera (net-winged insects) (Pohl and Beutel,...
Three whole-wood isotopic reference materials, USGS54, USGS55, and USGS56, for δ2H, δ13C, δ15N, and δ18O measurements
Haiping Qi, Tyler B. Coplen, James A. Jordan
2016, Chemical Geology (442) 47-53
Comparative measurements of stable hydrogen and oxygen isotopes in wood are hampered by the lack of proper reference materials (RMs). The U.S. Geological Survey (USGS) has prepared three powdered, whole-wood RMs, USGS54 (Pinus contorta, Canadian lodgepole pine), USGS55 (Cordia cf. dodecandra, Mexican ziricote), and USGS56 (Berchemia cf. zeyheri, South...
Age, distribution and style of deformation in Alaska north of 60°N: Implications for assembly of Alaska
Thomas E. Moore, Stephen E. Box
2016, Tectonophysics (691) 133-170
The structural architecture of Alaska is the product of a complex history of deformation along both the Cordilleran and Arctic margins of North America involving oceanic plates, subduction zones and strike-slip faults and with continental elements of Laurentia, Baltica, and Siberia. We use geological constraints to assign regions of deformation...
When winners become losers: Predicted nonlinear responses of arctic birds to increasing woody vegetation
Sarah J. Thompson, Colleen M. Handel, Rachel M. Richardson, Lance B. McNew
2016, PLoS ONE (11) 1-17
Climate change is facilitating rapid changes in the composition and distribution of vegetation at northern latitudes, raising questions about the responses of wildlife that rely on arctic ecosystems. One widely observed change occurring in arctic tundra ecosystems is an increasing dominance of deciduous shrub vegetation. Our goals were to examine...
Using thermal limits to assess establishment of fish dispersing to high-latitude and high-elevation watersheds
Karen M. Dunmall, Neil J. Mochnacz, Christian E. Zimmerman, Charles Lean, James D. Reist
2016, Canadian Journal of Fisheries and Aquatic Sciences (73) 1750-1758
Distributional shifts of biota to higher latitudes and elevations are presumably influenced by species-specific physiological tolerances related to warming temperatures. However, it is establishment rather than dispersal that may be limiting colonizations in these cold frontier areas. In freshwater ecosystems, perennial groundwater springs provide critical winter thermal refugia in these...
Climate-change signals in national atmospheric deposition program precipitation data
Gregory A. Wetherbee, M. Alisa Mast
2016, Climate Dynamics (47) 3141-3155
National Atmospheric Deposition Program (NADP)/National Trends Network precipitation type, snow-season duration, and annual timing of selected chemical wet-deposition maxima vary with latitude and longitude within a 35-year (1979–2013) data record for the contiguous United States and Alaska. From the NADP data collected within the region bounded by 35.6645°–48.782° north latitude...
Review of footnotes and annotations to the 1949–2013 tables of standard atomic weights and tables of isotopic compositions of the elements (IUPAC Technical Report)
Tyler B. Coplen, Norman E. Holden
2016, Pure and Applied Chemistry (88) 689-699
The Commission on Isotopic Abundances and Atomic Weights uses annotations given in footnotes that are an integral part of the Tables of Standard Atomic Weights to alert users to the possibilities of quite extraordinary occurrences, as well as sources with abnormal atomic-weight values outside an otherwise acceptable range. The basic...
Bacterial genomics reveal the complex epidemiology of an emerging pathogen in arctic and boreal ungulates
Taya L. Forde, Karin Orsel, Ruth N. Zadoks, Roman Biek, Layne G. Adams, Sylvia L. Checkley, Tracy Davison, Jeroen De Buck, Mathieu Dumond, Brett T. Elkin, Laura Finnegan, Bryan J. Macbeth, Cait Nelson, Amanda Niptanatiak, Shane Sather, Helen M. Schwantje, Frank van der Meer, Susan J. Kutz
2016, Frontiers in Microbiology (7) 1-14
Northern ecosystems are currently experiencing unprecedented ecological change, largely driven by a rapidly changing climate. Pathogen range expansion, and emergence and altered patterns of infectious disease, are increasingly reported in wildlife at high latitudes. Understanding the causes and consequences of shifting pathogen diversity and host-pathogen interactions in these ecosystems is...
