Soil respiration patterns and controls in limestone cedar glades
Jennifer M. Cartwright, Dafeng Hui
2015, Plant and Soil (389) 157-169
Aims Drivers of soil respiration (Rs) in rock outcrop ecosystems remain poorly understood. We investigated these drivers in limestone cedar glades, known for their concentrations of endemic plant species and for seasonal hydrologic extremes (xeric and saturated conditions), and compared our findings to those in temperate grasslands and semi-arid ecosystems. Methods We measured...
Radar attenuation and temperature within the Greenland Ice Sheet
Joseph A MacGregor, Jilu Li, John D Paden, Ginny A Catania, Gary D. Clow, Mark A Fahnestock, Prasad S. Gogineni, Robert E. Grimm, Mathieu Morlighem, Soumyaroop Nandi, Helene Seroussi, David E Stillman
2015, Journal of Geophysical Research F: Earth Surface (120) 1-26
The flow of ice is temperature-dependent, but direct measurements of englacial temperature are sparse. The dielectric attenuation of radio waves through ice is also temperature-dependent, and radar sounding of ice sheets is sensitive to this attenuation. Here we estimate depth-averaged radar-attenuation rates within the Greenland Ice Sheet from airborne radar-sounding...
Geologic control on the evolution of the inner shelf morphology offshore of the Mississippi barrier islands, northern Gulf of Mexico, USA
James G. Flocks, Jack L. Kindinger, Kyle W. Kelso
2015, Continental Shelf Research (101) 59-70
Between 2008 and 2013, high-resolution geophysical surveys were conducted around the Mississippi barrier islands and offshore. The sonar surveys included swath and single-beam bathymetry, sidescan, and chirp subbottom data collection. The geophysical data were groundtruthed using vibracore sediment collection. The results provide insight into the evolution of the inner shelf...
Desertification, salinization, and biotic homogenization in a dryland river ecosystem
S. Miyazono, Reynaldo Patino, C.M. Taylor
2015, Science of the Total Environment (511) 444-453
This study determined long-term changes in fish assemblages, river discharge, salinity, and local precipitation, and examined hydrological drivers of biotic homogenization in a dryland river ecosystem, the Trans-Pecos region of the Rio Grande/Rio Bravo del Norte (USA/Mexico). Historical (1977-1989) and current (2010-2011) fish assemblages were analyzed by rarefaction analysis (species...
Modeled intermittency risk for small streams in the Upper Colorado River Basin under climate change
Lindsay V. Reynolds, Patrick B. Shafroth, N. LeRoy Poff
2015, Journal of Hydrology (523) 768-780
Longer, drier summers projected for arid and semi-arid regions of western North America under climate change are likely to have enormous consequences for water resources and river-dependent ecosystems. Many climate change scenarios for this region involve decreases in mean annual streamflow, late summer precipitation and late-summer streamflow in the coming...
Spatiotemporal associations of reservoir nutrient characteristics and the invasive, harmful alga Prymnesium parvum in West Texas
Matthew M. VanLandeghem, Mukhtar Farooqi, Greg M. Southard, Reynaldo Patino
2015, Journal of the American Water Resources Association (51) 487-501
Golden alga (Prymnesium parvum) is a harmful alga that has caused ecological and economic harm in freshwater and marine systems worldwide. In inland systems of North America, toxic blooms have nearly eliminated fish populations in some systems. Modifying nutrient profiles through alterations to land or water use may be a...
Foraging range movements of the endangered Hawaiian hoary bat, Lasiurus cinereus semotus (Chiroptera: Vespertilionidae)
Frank J. Bonaccorso, Christopher M. Todd, Adam C. Miles, P. Marcos Gorresen
2015, Journal of Mammalogy (96) 64-71
We documented nightly movements of Hawaiian hoary bats (Lasiurus cinereus semotus) on the island of Hawai’i. Based on data from 28 radiotagged individuals mean foraging range (FR) was 230.7±72.3 ha, core-use area (CUA) was 25.5±6.9 ha (or 11.1% of mean FR), and the mean long axis (LAX) across the FR...
The Everglades Depth Estimation Network (EDEN) surface-water model, version 2
Pamela A. Telis, Zhixiao Xie, Zhongwei Liu, Yingru Li, Paul Conrads
2015, Scientific Investigations Report 2014-5209
The Everglades Depth Estimation Network (EDEN) is an integrated network of water-level gages, interpolation models that generate daily water-level and water-depth data, and applications that compute derived hydrologic data across the freshwater part of the greater Everglades landscape. The U.S. Geological Survey Greater Everglades Priority Ecosystems Science provides support for...
Habitat fragmentation in coastal southern California disrupts genetic connectivity in the cactus wren (Campylorhynchus brunneicapillus)
Kelly R. Barr, Barbara E. Kus, Kristine Preston, Scarlett L. Howell, Emily Perkins, Amy G. Vandergast
2015, Molecular Ecology (24) 2349-2363
Achieving long-term persistence of species in urbanized landscapes requires characterizing population genetic structure to understand and manage the effects of anthropogenic disturbance on connectivity. Urbanization over the past century in coastal southern California has caused both precipitous loss of coastal sage scrub habitat and declines in populations of the cactus...
Females exceed males in mercury concentrations of burbot Lota lota
Charles P. Madenjian, Martin A. Stapanian, Peter A. Cott, David P. Krabbenhoft, William Edwards, Lynn M. Ogilvie, Justin G. Mychek-Londer, John F. DeWild
2015, Archives of Environmental Contamination and Toxicology (68) 678-688
Examination of differences in contaminant concentrations between sexes of fish, across several fish species, may reveal clues for important behavioral and physiological differences between the sexes. We determined whole-fish total mercury (Hg) concentrations of 25 male and 25 female adult burbot Lota lota captured in Lake Erie during summer 2011,...
Consequences of habitat change and resource selection specialization for population limitation in cavity-nesting birds
Thomas E. Martin
2015, Journal of Applied Ecology (52) 475-485
Resource selection specialization may increase vulnerability of populations to environmental change. One environmental change that may negatively impact some populations is the broad decline of quaking aspen Populus tremuloides, a preferred nest tree of cavity-nesting organisms who are commonly limited by nest-site availability. However, the long-term consequences of...
Seismic source dynamics of gas-piston activity at Kı̄lauea Volcano, Hawai‘i
Bernard A. Chouet, Phillip B. Dawson
2015, Journal of Geophysical Research B: Solid Earth (120) 2525-2560
Since 2008, eruptive activity at the summit of Kı̄lauea Volcano, Hawai‘i has been confined to the new Overlook pit crater within the Halema‘uma‘u Crater. Among the broad range of magmatic processes observed in the new pit are recurring episodes of gas pistoning. The gas-piston activity is accompanied by seismic signals...
Predicting ecological responses of the Florida Everglades to possible future climate scenarios: Introduction
Nicholas G. Aumen, Karl E Havens, G. Ronnie Best, Leonard Berry
2015, Environmental Management (55) 741-748
Florida’s Everglades stretch from the headwaters of the Kissimmee River near Orlando to Florida Bay. Under natural conditions in this flat landscape, water flowed slowly downstream as broad, shallow sheet flow. The ecosystem is markedly different now, altered by nutrient pollution and construction of canals, levees, and water control structures...
Slab melting beneath the Cascades Arc driven by dehydration of altered oceanic peridotite
Kristina J Walowski, Paul J. Wallace, E.H. Hauri, I. Wada, Michael A. Clynne
2015, Nature Geoscience (8) 404-408
Water is returned to Earth’s interior at subduction zones. However, the processes and pathways by which water leaves the subducting plate and causes melting beneath volcanic arcs are complex; the source of the water—subducting sediment, altered oceanic crust, or hydrated mantle in the downgoing plate—is debated; and the role of...
Post-White-nose syndrome trends in Virginia’s cave bats, 2008-2013
Karen E. Powers, Richard J. Reynolds, Wil Orndorff, W. Mark Ford, Christopher S. Hobson
2015, Journal of Ecology and the Natural Environment (7) 113-123
Since its 2009 detection in Virginia hibernacula, the fungal pathogen Pseudogymnoascus destructans causing White-nose Syndrome (WNS) has had a marked impact on cave bats locally. From 2008-2013, we documented numeric and physiologic changes in cave bats through fall swarm (FS), early hibernation (EH), and late hibernation (LH) capture and banding...
Factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the outer banks of North Carolina
Shiloh A. Schulte, Theodore R. Simons
2015, Marine Ornithology: Journal of Seabird Research and Conservation (43) 37-47
We used an information-theoretic approach to assess the factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the Outer Banks of North Carolina. We evaluated survival with respect to nesting island, year, time of season, brood age, distance to tide (m), presence of off-road vehicles and...
Landowner perceptions of three types of boating in the Saranac Lakes area of New York State׳s Adirondack Park
Diane Kuehn, Rudy Schuster, Erik Nordman
2015, Journal of Outdoor Recreation and Tourism (9) 53-63
In order for natural resource managers to better understand conflicting landowner perspectives related to non-motorized, motorized, and personal watercraft use, this study examines the demographic and experiential characteristics, values, attitudes, and beliefs of landowners in the Saranac Lakes area of the Adirondack Park in New York State. A mixed-methods approach,...
Coastal evidence for Holocene subduction-zone earthquakes and tsunamis in central Chile
Tina Dure, Marco Cisternas, Benjamin Horton, Lisa Ely, Alan R. Nelson, Robert L. Wesson, Jessica Pilarczyk
2015, Quaternary Science Reviews (113) 93-111
The ∼500-year historical record of seismicity along the central Chile coast (30–34°S) is characterized by a series of ∼M 8.0–8.5 earthquakes followed by low tsunamis (<4 m) occurring on the megathrust about every 80 years. One exception is the AD 1730 great earthquake (M 9.0–9.5) and high tsunami (>10 m), but the...
A tribute to George Plafker
Gary S. Fuis, Peter J. Haeussler, Brian F. Atwater
2015, Quaternary Science Reviews (113) 3-7
In a long and distinguished career, George Plafker made fundamental advances in understanding of megathrust tectonics, tsunami generation, paleoseismology, crustal neotectonics, and Alaskan geology, chiefly by means of geological field observations. George discovered that giant earthquakes result from tens of meters of seismic slip on subduction megathrusts, and he did this...
Simulated high-latitude soil thermal dynamics during the past four decades
S. Peng, P. Ciais, T. Wang, I. Gouttevin, A. D. McGuire, D. Lawrence, E. Burke, X. Chen, C. Delire, C. Koven, A. MacDougall, A. Rinke, K. Saito, W. Zhang, R. Alkama, T. J. Bohn, B. Decharme, T. Hajima, D. Ji, D.P. Lettenmaier, P.A. Miller, J.C. Moore, B. Smith, T. Sueyoshi
2015, Cryosphere Discussions (9) 2301-2337
Soil temperature (Ts ) change is a key indicator of the dynamics of permafrost. On seasonal and inter-annual time scales, the variability of Ts determines the active layer depth, which regulates hydrological soil properties and biogeochemical processes. On the multi-decadal scale, increasing T 5 s not only drives permafrost thaw/retreat,...
Understanding the Day Cent model: Calibration, sensitivity, and identifiability through inverse modeling
Magdalena Necpalova, Robert P. Anex, Michael N. Fienen, Stephen J. Del Grosso, Michael J. Castellano, John E. Sawyer, Javed Iqbal, Jose L. Pantoja, Daniel W. Barker
2015, Environmental Modelling and Software (66) 110-130
The ability of biogeochemical ecosystem models to represent agro-ecosystems depends on their correct integration with field observations. We report simultaneous calibration of 67 DayCent model parameters using multiple observation types through inverse modeling using the PEST parameter estimation software. Parameter estimation reduced the total sum of weighted squared residuals by...
Expanding metal mixture toxicity models to natural stream and lake invertebrate communities
Laurie S. Balistrieri, Christopher A. Mebane, Travis S. Schmidt, William (Bill) Keller
2015, Environmental Toxicology and Chemistry (34) 761-776
A modeling approach that was used to predict the toxicity of dissolved single and multiple metals to trout is extended to stream benthic macroinvertebrates, freshwater zooplankton, and Daphnia magna. The approach predicts the accumulation of toxicants (H, Al, Cd, Cu, Ni, Pb, and Zn) in organisms using 3 equilibrium accumulation...
Polygonal tundra geomorphological change in response to warming alters future CO2 and CH4 flux on the Barrow Peninsula
Mark J. Lara, A. David McGuire, Eugénie S. Euskirchen, Craig E. Tweedie, Kenneth M. Hinkel, Alexei N. Skurikhin, Vladimir E. Romanovsky, Guido Grosse, W. Robert Bolton, Helene Genet
2015, Global Change Biology (21) 1634-1651
The landscape of the Barrow Peninsula in northern Alaska is thought to have formed over centuries to millennia, and is now dominated by ice-wedge polygonal tundra that spans drained thaw-lake basins and interstitial tundra. In nearby tundra regions, studies have identified a rapid increase in thermokarst formation (i.e., pits) over...
A comparison between boat-based and diver-based methods for quantifying coral bleaching
David G. Zawada, Rob Ruzicka, Michael A. Colella
2015, Journal of Experimental Marine Biology and Ecology (467) 39-44
Recent increases in both the frequency and severity of coral bleaching events have spurred numerous surveys to quantify the immediate impacts and monitor the subsequent community response. Most of these efforts utilize conventional diver-based methods, which are inherently time-consuming, expensive, and limited in spatial scope unless they deploy large teams...
A pan-Arctic synthesis of CH4 and CO2 production from anoxic soil incubations
Claire C. Treat, Susan M. Natali, Jessica Ernakovich, Colleen M. Iverson, Massimo Lupasco, A. David McGuire, Richard J. Norby, Taniya Roy Chowdhury, Andreas Richter, Hana Santruckova, C. Schädel, Edward A.G. Schuur, Victoria L. Sloan, Merritt R. Turetsky, Mark P. Waldrop
2015, Global Change Biology (21) 2787-2803
Permafrost thaw can alter the soil environment through changes in soil moisture, frequently resulting in soil saturation, a shift to anaerobic decomposition, and changes in the plant community. These changes, along with thawing of previously frozen organic material, can alter the form and magnitude of greenhouse gas production from permafrost...
