Tectonic activity as a significant source of crustal tetrafluoromethane emissions to the atmosphere: observations in groundwaters along the San Andreas Fault
Daniel A. Deeds, Justin T. Kulongoski, Jens Muhle, Ray F. Weiss
2015, Earth and Planetary Science Letters (412) 163-172
Tetrafluoromethane (CF4) concentrations were measured in 14 groundwater samples from the Cuyama Valley, Mil Potrero and Cuddy Valley aquifers along the Big Bend section of the San Andreas Fault System (SAFS) in California to assess whether tectonic activity in this region is a significant source of crustal CF4 to the...
Temperature effects induced by climate change on the growth and consumption by salmonines in Lakes Michigan and Huron
Yu-Chun Kao, Charles P. Madenjian, David B. Bunnell, Brent M. Lofgren, Marjorie Perroud
2015, Environmental Biology of Fishes (98) 1089-1104
We used bioenergetics models to investigate temperature effects induced by climate change on the growth and consumption by Chinook salmon Oncorhynchus tshawytscha, lake trout Salvelinus namaycush, and steelhead O. mykiss in Lakes Michigan and Huron. We updated biological inputs to account for recent changes in the food webs and used temperature inputs in response...
Time scales of porphyry Cu deposit formation: insights from titanium diffusion in quartz
Celestine N. Mercer, Mark H. Reed, Cameron M. Mercer
2015, Economic Geology (110) 587-602
Porphyry dikes and hydrothermal veins from the porphyry Cu-Mo deposit at Butte, Montana, contain multiple generations of quartz that are distinct in scanning electron microscope-cathodoluminescence (SEM-CL) images and in Ti concentrations. A comparison of microprobe trace element profiles and maps to SEM-CL images shows that the concentration of Ti in...
Mineral Resource of the Month: Antimony
David E. Guberman
2015, Earth Magazine (February 2015)
Antimony is a lustrous silvery-white semimetal or metalloid. Archaeological and historical studies indicate that antimony and its mineral sulfides have been used by humans for at least six millennia. The alchemist Basil Valentine is sometimes credited with “discovering” the element; he described the extraction of metallic antimony from stibnite in...
The cost of reproduction: differential resource specialization in female and male California sea otters
Emma A. Elliott Smith, Seth D. Newsome, James A. Estes, M. Tim Tinker
2015, Oecologia (178) 17-29
Intraspecific variation in behavior and diet can have important consequences for population and ecosystem dynamics. Here, we examine how differences in reproductive investment and spatial ecology influence individual diet specialization in male and female southern sea otters (Enhydra lutris nereis). We hypothesize that greater reproductive constraints and smaller home...
Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes
Kurt P. Kowalski, Charles W. Bacon, Wesley A. Bickford, Heather A. Braun, Keith Clay, Michele Leduc-Lapierre, Elizabeth Lillard, Melissa K. McCormick, Eric Nelson, Monica Torres, James W. C. White, Douglas A. Wilcox
2015, Frontiers in Microbiology (6)
A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into...
Hillslope run-off thresholds with shrink–swell clay soils
Ryan D. Stewart, Majdi R. Abou Najm, David E. Rupp, John W. Lane Jr., Hamil C. Uribe, Jose Luis Arumi, John S. Selker
2015, Hydrological Processes (29) 557-571
Irrigation experiments on 12 instrumented field plots were used to assess the impact of dynamic soil crack networks on infiltration and run-off. During applications of intensity similar to a heavy rainstorm, water was seen being preferentially delivered within the soil profile. However, run-off was not observed until soil water content...
Do shrubs reduce the adverse effects of grazing on soil properties?
David J. Eldridge, Genevieve Beecham, James B. Grace
2015, Ecohydrology (8) 1503-1513
Increases in the density of woody plants are a global phenomenon in drylands, and large aggregations of shrubs, in particular, are regarded as being indicative of dysfunctional ecosystems. There is increasing evidence that overgrazing by livestock reduces ecosystem functions in shrublands, but that shrubs may buffer the negative effects of...
Preliminary evaluation of an in vivo fluorometer to quantify algal periphyton biomass and community composition
Theodore D. Harris, Jennifer L. Graham
2015, Lake and Reservoir Management (31) 127-133
The bbe-Moldaenke BenthoTorch (BT) is an in vivo fluorometer designed to quantify algal biomass and community composition in benthic environments. The BT quantifies total algal biomass via chlorophyll a (Chl-a) concentration and may differentiate among cyanobacteria, green algae, and diatoms based on pigment fluorescence. To evaluate how BT measurements of...
Sources of fine sediment stored in agricultural lowland streams, Midwest, USA
Jasmeet Lamba, Anita M. Thompson, K.G. Karthikeyan, Faith A. Fitzpatrick
2015, Geomorphology (236) 44-53
Agricultural activities can accelerate the offsite transport of productive soil from fields leading to stream water quality degradation. Identification of the nature and relative contribution of different sources to fine-grained sediment (e.g., silts, clays) in streams is important to effectively focus agricultural best management...
Microscopical characterization of carbon materials derived from coal and petroleum and their interaction phenomena in making steel electrodes, anodes and cathode blocks for the Microscopy of Carbon Materials Working Group of the ICCP
G. Predeanu, C. Panaitescu, M. Bălănescu, G. Bieg, A.G. Borrego, M. A. Diez, Paul C. Hackley, B. Kwiecinska, M. Marques, Maria Mastalerz, M. Misz-Kennan, S. Pusz, I. Suarez-Ruiz, S. Rodrigues, A. K. Singh, A. K. Varma, A. Zdravkov, D. Zivotić
2015, International Journal of Coal Geology (139) 63-79
This paper describes the evaluation of petrographic textures representing the structural organization of the organic matter derived from coal and petroleum and their interaction phenomena in the making of steel electrodes, anodes and cathode blocks.This work represents the results of the Microscopy of Carbon Materials Working Group in...
Aeolian responses to climate variability during the past century on Mesquite Lake Playa, Mojave Desert
John W. Whitney, George N. Breit, S.E. Buckingham, Richard L. Reynolds, Rian C. Bogle, Lifeng Luo, Harland L. Goldstein, John M. Vogel
2015, Geomorphology (230) 13-25
The erosion and deposition of sediments by wind from 1901 to 2013 have created large changes in surface features of Mesquite Lake playa in the Mojave Desert. The decadal scale recurrence of sand-sheet development, migration, and merging with older dunes appears related to decadal climatic changes of drought and wetness...
Suspended-sediment trapping in the tidal reach of an estuarine tributary channel
Maureen A. Downing-Kunz, David H. Schoellhamer
2015, Estuaries and Coasts (38) 2198-2212
Evidence of decreasing sediment supply to estuaries and coastal oceans worldwide illustrates the need for accurate and updated estimates. In the San Francisco Estuary (Estuary), recent research suggests a decrease in supply from its largest tributaries, implying the increasing role of smaller, local tributaries in sediment supply to this estuary....
Variations in community exposure to lahar hazards from multiple volcanoes in Washington State (USA)
Angela K. Diefenbach, Nathan J. Wood, John W. Ewert
2015, Journal of Applied Volcanology (4)
Understanding how communities are vulnerable to lahar hazards provides critical input for effective design and implementation of volcano hazard preparedness and mitigation strategies. Past vulnerability assessments have focused largely on hazards posed by a single volcano, even though communities and officials in many parts of the world must plan for...
Reducing nitrogen export from the corn belt to the Gulf of Mexico: agricultural strategies for remediating hypoxia
Eileen McLellan, Dale M. Robertson, Keith Schilling, Mark Tomer, Jill Kostel, Douglas G. Smith, Kevin King
2015, Journal of the American Water Resources Association (51) 263-289
SPAtially Referenced Regression on Watershed models developed for the Upper Midwest were used to help evaluate the nitrogen-load reductions likely to be achieved by a variety of agricultural conservation practices in the Upper Mississippi-Ohio River Basin (UMORB) and to compare these reductions to the 45% nitrogen-load reduction proposed to remediate...
Vegetation burn severity mapping using Landsat-8 and WorldView-2
Zhuoting Wu, Barry R. Middleton, Robert Hetzler, John M. Vogel, Dennis G. Dye
2015, Photogrammetric Engineering and Remote Sensing (2) 143-154
We used remotely sensed data from the Landsat-8 and WorldView-2 satellites to estimate vegetation burn severity of the Creek Fire on the San Carlos Apache Reservation, where wildfire occurrences affect the Tribe's crucial livestock and logging industries. Accurate pre- and post-fire canopy maps at high (0.5-meter) resolution were created from...
Assessing the likely effectiveness of multispecies management for imperiled desert fishes with niche overlap analysis
P Laub, Phaedra E. Budy
2015, Conservation Biology (29) 1153-1163
A critical decision in species conservation is whether to target individual species or a complex of ecologically similar species. Management of multispecies complexes is likely to be most effective when species share similar distributions, threats, and response to threats. We used niche overlap analysis to assess ecological similarity of...
Geochemical conditions and the occurrence of selected trace elements in groundwater basins used for public drinking-water supply, Desert and Basin and Range hydrogeologic provinces, 2006-11: California GAMA Priority Basin Project
Michael T. Wright, Miranda S. Fram, Kenneth Belitz
2015, Scientific Investigations Report 2014-5173
The geochemical conditions, occurrence of selected trace elements, and processes controlling the occurrence of selected trace elements in groundwater were investigated in groundwater basins of the Desert and Basin and Range (DBR) hydrogeologic provinces in southeastern California as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring...
Geomorphology and flood-plain vegetation of the Sprague and lower Sycan Rivers, Klamath Basin, Oregon
James E. O'Connor, Patricia F. McDowell, Pollyanna Lind, Christine G. Rasmussen, Mackenzie K. Keith
2015, Scientific Investigations Report 2014-5223
This study provides information on channel and flood-plain processes and historical trends to guide effective restoration and monitoring strategies for the Sprague River Basin, a primary tributary (via the lower Williamson River) of Upper Klamath Lake, Oregon. The study area covered the lower, alluvial segments of the Sprague River system,...
Data Collection and Simulation of Ecological Habitat and Recreational Habitat in the Shenandoah River, Virginia
Jennifer L. Krstolic
2015, Scientific Investigations Report 2015-5005
This report presents updates to methods, describes additional data collected, documents modeling results, and discusses implications from an updated habitat-flow model that can be used to predict ecological habitat for fish and recreational habitat for canoeing on the main stem Shenandoah River in Virginia. Given a 76-percent increase in population...
Characterizing the distribution of an endangered salmonid using environmental DNA analysis
Matthew B. Laramie, David S. Pilliod, Caren S. Goldberg
2015, Biological Conservation (183) 29-37
Determining species distributions accurately is crucial to developing conservation and management strategies for imperiled species, but a challenging task for small populations. We evaluated the efficacy of environmental DNA (eDNA) analysis for improving detection and thus potentially refining the known distribution of Chinook salmon (Oncorhynchus tshawytscha) in the Methow and...
Quantification of eDNA shedding rates from invasive bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix
Katy E. Klymus, Cathy A. Richter, Duane Chapman, Craig P. Paukert
2015, Biological Conservation (183) 77-84
Wildlife managers can more easily mitigate the effects of invasive species if action takes place before a population becomes established. Such early detection requires sensitive survey tools that can detect low numbers of individuals. Due to their high sensitivity, environmental DNA (eDNA) surveys hold promise as an early detection method...
Geographically isolated wetlands: Rethinking a misnomer
David M. Mushet, Aram J.K. Calhoun, Laurie C. Alexander, Matthew J. Cohen, Edward S. DeKeyser, Laurie G. Fowler, Charles R. Lane, Megan W. Lang, Mark C. Rains, Susan C. Walls
2015, Wetlands (35) 423-431
We explore the category “geographically isolated wetlands” (GIWs; i.e., wetlands completely surrounded by uplands at the local scale) as used in the wetland sciences. As currently used, the GIW category (1) hampers scientific efforts by obscuring important hydrological and ecological differences among multiple wetland functional types, (2) aggregates wetlands in...
The influence of disturbed habitat on the spatial ecology of Argentine black and white tegu (Tupinambis merianae), a recent invader in the Everglades ecosystem (Florida, USA)
Page E. Klug, Robert N. Reed, Frank J. Mazzotti, Michelle A. McEachern, Joy J. Vinci, Katelin K. Craven, Amy A. Yackel Adams
2015, Biological Invasions (17) 1785-1797
The threat of invasive species is often intensified in disturbed habitat. To optimize control programs, it is necessary to understand how degraded habitat influences the behavior of invasive species. We conducted a radio telemetry study to characterize movement and habitat use of introduced male Argentine black and white tegus (Tupinambis...
Intercontinental genetic structure and gene flow in Dunlin (Calidris alpina), a potential vector of avian influenza
Mark P. Miller, Susan M. Haig, Thomas D. Mullins, Luzhang Ruan, Bruce Casler, Alexei Dondua, H. River Gates, J. Matthew Johnson, Steven J. Kendall, Pavel S. Tomkovich, Diane Tracy, Olga P. Valchuk, Richard B. Lanctot
2015, Evolutionary Applications (8) 149-171
Waterfowl (Anseriformes) and shorebirds (Charadriiformes) are the most common wild vectors of influenza A viruses. Due to their migratory behavior, some may transmit disease over long distances. Migratory connectivity studies can link breeding and nonbreeding grounds while illustrating potential interactions among populations that may spread diseases. We investigated Dunlin (Calidris...
