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...
Flow cytometric method for measuring chromatin fragmentation in fixed sperm from yellow perch (Perca flavescens)
Jill A. Jenkins, Rassa O. Draugelis-Dale, Alfred E. Pinkney, Luke R. Iwanowicz, Vicki Blazer
2015, Theriogenology (83) 920-931
Declining harvests of yellow perch, Perca flavescens, in urbanized watersheds of Chesapeake Bay have prompted investigations of their reproductive fitness. The purpose of this study was to establish a flow cytometric technique for DNA analysis of fixed samples sent from the field to provide reliable gamete quality measurements. Similar to the...
Aquatic invertebrate food base for waterbirds at Wetland Reserve Program easements in the lower Mississippi Alluvial Valley
Jessica L. Tapp, Elisabeth B. Webb
2015, Wetlands (35) 183-192
Migratory waterbirds depend on invertebrates as a key source of dietary protein, but few studies have quantified aquatic invertebrates or their response to management on privately owned wetlands. Our objectives were to quantify the effects of wetland management provided through the Migratory Bird Habitat Initiative (MBHI) on invertebrate biomass, family...
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...
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...
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...
Genetic diversity and host specificity varies across three genera of blood parasites in ducks of the Pacific Americas Flyway
Andrew B. Reeves, Matthew M. Smith, Brandt W. Meixell, Joseph P. Fleskes, Andrew M. Ramey
2015, PLoS ONE (10)
Birds of the order Anseriformes, commonly referred to as waterfowl, are frequently infected by Haemosporidia of the genera Haemoproteus, Plasmodium, and Leucocytozoon via dipteran vectors. We analyzed nucleotide sequences of the Cytochrome b (Cytb) gene from parasites of these genera detected in six species of ducks from Alaska and California,...
Vegetation and non-native ungulate monitoring at the Big Island National Wildlife Refuge Complex 2010–2014.
Steven C. Hess, Christina R. Leopold, Steven J. Kendall
2015, Technical Report HCSU-062
The Hakalau Forest Unit (HFU) of Big Island National Wildlife Refuge Complex (BINWRC) has intensively managed feral cattle (Bos taurus) and pigs (Sus scrofa) and monitored non-native ungulate presence and distribution during surveys of all managed areas since 1988. We: 1) provide results from recent ungulate surveys at HFU to...
Magmatic gas emissions at Holocene volcanic features near Mono Lake, California, and their relation to regional magmatism
D. Bergfeld, William C. Evans, James F. Howle, Andrew G. Hunt
2015, Journal of Volcanology and Geothermal Research (292) 70-83
Silicic lavas have erupted repeatedly in the Mono Basin over the past few thousand years, forming the massive domes and coulees of the Mono Craters chain and the smaller island vents in Mono Lake. We report here on the first systematic study of magmatic CO2 emissions from these features, conducted during...
Evaluation of satellite rainfall estimates for drought and flood monitoring in Mozambique
Carolien Tote, Domingos Patricio, Hendrik Boogaard, Raymond van der Wijngaart, Elena Tarnavsky, Christopher C. Funk
2015, Remote Sensing (7) 1758-1776
Satellite derived rainfall products are useful for drought and flood early warning and overcome the problem of sparse, unevenly distributed and erratic rain gauge observations, provided their accuracy is well known. Mozambique is highly vulnerable to extreme weather events such as major droughts and floods and thus, an understanding of...
Factors influencing CO2 and CH4 emissions from coastal wetlands in the Liaohe Delta, northeast China
Linda Olsson, Siyuan Ye, Xueyang Yu, Mengjie Wei, Ken W. Krauss, Hans Brix
2015, Biogeosciences Discussions (12) 3469-3503
Many factors are known to influence greenhouse gas emissions from coastal wetlands, but it is still unclear which factors are most important under field conditions when they are all acting simultaneously. The objective of this study was to assess the effects of water table, salinity, soil temperature and vegetation on...
Genomics and introgression: Discovery and mapping of thousands of species-diagnostic SNPs using RAD sequencing
Brian K. Hand, Tyler D Hether, Ryan P. Kovach, Clint C. Muhlfeld, Stephen J. Amish, Matthew C. Boyer, Sean M. O’Rourke, Michael R. Miller, Winsor H. Lowe, Paul A. Hohenlohe, Gordon Luikart
2015, Current Zoology (61) 146-154
Invasive hybridization and introgression pose a serious threat to the persistence of many native species. Understanding the effects of hybridization on native populations (e.g., fitness consequences) requires numerous species-diagnostic loci distributed genome-wide. Here we used RAD sequencing to discover thousands of single-nucleotide polymorphisms (SNPs) that are diagnostic between rainbow trout...
Ground motion observations of the 2014 South Napa earthquake
Annemarie S. Baltay Sundstrom, John Boatwright
2015, Seismological Research Letters (86) 355-360
Ground motions of the South Napa earthquake (24 August 2014; M 6.0) were recorded at 19 stations within 20 km and 292 stations within 100 km of the rupture surface trace, generating peak ground motions in excess of 50%g and 50 cm/s in and near Napa Valley. This large dataset allows us to compare the...
Inter-annual and spatial variability of Hamon potential evapotranspiration model coefficients
Gregory J. McCabe, Lauren E. Hay, Andy Bock, Steven L. Markstrom, R. Dwight Atkinson
2015, Journal of Hydrology (521) 389-394
Monthly calibrated values of the Hamon PET coefficient (C) are determined for 109,951 hydrologic response units (HRUs) across the conterminous United States (U.S.). The calibrated coefficient values are determined by matching calculated mean monthly Hamon PET to mean monthly free-water surface evaporation. For most locations and months the calibrated coefficients...
Ecosystem-atmosphere exchange of CO2 in a temperate herbaceous peatland in the Sanjiang Plain of northeast China
Xiaoyan Zhu, Changchun Song, Christopher M. Swarzenski, Yuedong Guo, Xinhow Zhang, Jiaoyue Wang
2015, Ecological Engineering (75) 16-23
Northern peatlands contain a considerable share of the terrestrial carbon pool, which will be affected by future climatic variability. Using the static chamber technique, we investigated ecosystem respiration and soil respiration over two growing seasons (2012 and 2013) in a Carex lasiocarpa-dominated peatland in the Sanjiang Plain in China. We...
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....
Petrologic testament to changes in shallow magma storage and transport during 30+ years of recharge and eruption at Kīlauea Volcano, Hawai‘i
Carl R. Thornber, Tim R. Orr, Christina Heliker, Richard P. Hoblitt
Rebecca Carey, Valerie Cayol, Michael P. Poland, Dominique Weis, editor(s)
2015, Geophysical Monograph 8
Petrologic monitoring of Kīlauea Volcano from January 1983 to October 2013 has yielded an extensive record of glass, phenocryst, melt inclusion, and bulk-lava chemistry from well-quenched lava. When correlated with 30+ years of geophysical and geologic monitoring, petrologic details testify to physical maturation of summit-to-rift magma plumbing associated with...
Development of a new semi-analytical model for cross-borehole flow experiments in fractured media
Delphine Roubinet, James Irving, Frederick D. Day-Lewis
2015, Advances in Water Resources (76) 97-108
Analysis of borehole flow logs is a valuable technique for identifying the presence of fractures in the subsurface and estimating properties such as fracture connectivity, transmissivity and storativity. However, such estimation requires the development of analytical and/or numerical modeling tools that are well adapted to the complexity of the problem....
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...
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...
DigitalCrust – a 4D data system of material properties for transforming research on crustal fluid flow
Yin Fan, Steve Richard, R. Sky Bristol, Shanan Peters, Steven E. Ingebritsen, Nils Moosdorf, Aaron I. Packman, Tom Gleeson, Ilya Zazlavsky, Scott Peckham, Larry Murdoch, Michael Cardiff, David Tarboton, Norm Jones, Richard Hooper, Jennifer Arrigo, David Gochis, John Olson
2015, Geofluids (15) 372-379
Fluid circulation in the Earth's crust plays an essential role in surface, near surface, and deep crustal processes. Flow pathways are driven by hydraulic gradients but controlled by material permeability, which varies over many orders of magnitude and changes over time. Although millions of measurements of crustal properties have been...
The role of water in unconventional in situ energy resource extraction technologies
Tanya J. Gallegos, Carleton R. Bern, Justin E. Birdwell, Seth S. Haines, Mark A. Engle
Satinder Ahuja, editor(s)
2015, Book chapter, Food, energy, and water: The chemistry connection
Global trends toward developing new energy resources from lower grade, larger tonnage deposits that are not generally accessible using “conventional” extraction methods involve variations of subsurface in situ extraction techniques including in situ oil shale retorting, hydraulic fracturing of petroleum reservoirs, and in situ recovery of uranium. Although these methods are...
A method for estimating the diffuse attenuation coefficient (KdPAR)from paired temperature sensors
Jordan S. Read, Kevin C. Rose, Luke A. Winslow, Emily K. Read
2015, Limnology and Oceanography: Methods (13) 53-61
A new method for estimating the diffuse attenuation coefficient for photosynthetically active radiation (KdPAR) from paired temperature sensors was derived. We show that during cases where the attenuation of penetrating shortwave solar radiation is the dominant source of temperature changes, time series measurements of water temperatures at multiple depths (z1 and z2)...
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...
Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers
James H. Larson, Michelle Bartsch, Steve Gutreuter, Brent C. Knights, Lynn Bartsch, William B. Richardson, Jonathan M. Vallazza, Michael T. Arts
2015, Inland Waters (5) 101-106
Large river systems are often thought to contain a mosaic of patches with different habitat characteristics driven by differences in flow and mixing environments. Off-channel habitats (e.g., backwater areas, secondary channels) can become semi-isolated from main-channel water inputs, leading to the development of distinct biogeochemical environments. Observations of adult bluegill...
