Impacts of mineralogical variation on CO2 behavior in small pores from producing intervals of the Marcellus Shale: Results from neutron scattering
Leslie F. Ruppert, Aaron M. Jubb, Thomas F Headen, Tristan G. A. Youngs, Bryan Bandli
2020, Energy & Fuels (34) 2765-2771
The Near and InterMediate Range Order Diffractometer (NIMROD) was used to examine the potential impact of shale mineralogy on CO2 behavior within micropores. Two samples with varying mineral compositions were obtained from producing intervals in the dry gas window in the Middle...
Genes in space: What Mojave desert tortoise genetics can tell us about landscape connectivity
Kirsten E. Dutcher, Amy G. Vandergast, Todd Esque, Anna Mitelberg, Marjorie D Matocq, Jill S. Heaton, Ken E Nussear
2020, Conservation Genetics (21) 289-303
Habitat loss and fragmentation in the Mojave Desert have been increasing, which can create barriers to movement and gene flow leading to decreased populations of native species. Disturbance and degradation of Mojave desert tortoise habitat includes linear features (e.g. highways, railways, and a network of dirt roads), urbanized areas, and...
A random forest approach for bounded outcome variables
Leonie Weinhold, Matthias Schmid, Richard M. Mitchell, Kelly O. Maloney, Marvin N. Wright, Moritz Berger
2020, Journal of Computational and Graphical Statistics (29) 639-658
Random forests have become an established tool for classication and regres- sion, in particular in high-dimensional settings and in the presence of non-additive predictor-response relationships. For bounded outcome variables restricted to the unit interval, however, classical modeling approaches based on mean squared error loss may severely suer as they do not account for heteroscedasticity...
Hydrologic connectivity determines dissolved organic matter biogeochemistry in northern high-latitude lakes
Sarah Ellen Johnston, Robert G. Striegl, Matthew J. Bogard, Mark M. Dornblaser, David E. Butman, Anne M. Kellerman, Kimberly P. Wickland, David C. Podgorski, Robert G. M. Spencer
2020, Limnology and Oceanography (65) 1764-1780
Northern high‐latitude lakes are undergoing climate‐induced changes including shifts in their hydrologic connectivity with terrestrial ecosystems. How this will impact dissolved organic matter (DOM) biogeochemistry remains uncertain. We examined the drivers of DOM composition for lakes in the Yukon Flats Basin in Alaska, an arid region of low relief that...
Northward migration of the Oregon forearc on the Gales Creek fault
Ray Wells, Richard J. Blakely, Sean Bemis
2020, Geosphere (16) 660-684
The Gales Creek fault (GCF) is a 60-km-long, northwest-striking dextral fault system (west of Portland, Oregon) that accommodates northward motion and uplift of the Oregon Coast Range. New geologic mapping and geophysical models confirm inferred offsets from earlier geophysical surveys and document ∼12 km of right-lateral offset...
A weight-of-evidence approach for defining thermal sensitivity in a federally endangered species
Heather Galbraith, Carrie J. Blakeslee, Daniel E. Spooner, William A. Lellis
2020, Aquatic Conservation: Marine and Freshwater Ecosystems (30) 540-553
1. Managing for threatened and endangered species under changing environmental conditions is a challenge faced by resource managers worldwide. Lack of basic knowledge of the biology and habitat requirements of these species can contribute to this difficulty, but is confounded by the limitations of working with rare (i.e. few individuals)...
Discrimination of biological scatterers in polarimetric weather radar data: Opportunities and challenges
Sidney Gauthreaux, Robert H. Diehl
2020, Remote Sensing (12)
For radar aeroecology studies, the identification of the type of scatterer is critically important. Here, we used a random forest (RF) algorithm to develop a variety of scatterer classification models based on the backscatter values in radar resolution volumes of six radar variables (reflectivity, radial velocity, spectrum width, differential...
Evidence of wildfires and elevated atmospheric oxygen at the Frasnian–Famennian boundary in New York (USA): Implications for the Late Devonian mass extinction
Zeyang Liu, David Selby, Paul C. Hackley, Jeffrey Over
2020, Geological Society of America Bulletin (132) 2043-2054
The Devonian Period experienced significant fluctuations of atmospheric oxygen (O2) levels (∼25–13%), for which the extent and timing are debated. Also characteristic of the Devonian Period, at the Frasnian–Famennian (F–F) boundary, is one of the “big five” mass extinction events of the Phanerozoic. Fossilized charcoal...
Meteotsunamis triggered by tropical cyclones
Maitane Olabarrieta, Luming Shi, David Nolan, John C. Warner
2020, Nature Communications (11)
Tropical cyclones are one of the most destructive natural hazards and much of the damage and casualties they cause are flood-related. Accurate characterization and prediction of total water levels during extreme storms is necessary to minimize coastal impacts. While meteotsunamis are known to influence water levels and to produce severe...
Carbon release through abrupt permafrost thaw
Merritt R. Turetsky, Benjamin W. Abbott, Miriam C. Jones, Katey Walter Anthony, David Olefeldt, Edward A. Schuur, Guido Grosse, Peter Kuhry, Gustaf Hugelius, Charles Koven, David M. Lawrence, Carolyn Gibson, A. Britta K. Sannel, A.D. McGuire
2020, Nature Geoscience (13) 138-143
The permafrost zone is expected to be a substantial carbon source to the atmosphere, yet large-scale models currently only simulate gradual changes in seasonally thawed soil. Abrupt thaw will probably occur in <20% of the permafrost zone but could affect half of permafrost carbon through collapsing ground, rapid erosion and landslides. Here,...
Divergent genes encoding the putative receptors for growth hormone and prolactin in sea lamprey display distinct patterns of expression
Ningping Gong, Diogo Ferreira-Martins, Stephen D. McCormick, Mark Sheridan
2020, Scientific Reports (10)
Growth hormone receptor (GHR) and prolactin receptor (PRLR) in jawed vertebrates were thought to arise after the divergence of gnathostomes from a basal vertebrate. In this study we have identified two genes encoding putative GHR and PRLR in sea lamprey (Petromyzon marinus) and Arctic lamprey (Lethenteron camtschaticum), extant members of...
Influence of population density and length structure on angler catch rate in kokanee fisheries
Zachary B. Klein, Michael C. Quist, Daniel J. Schill, Andrew M. Dux, Matthew P. Corsi
2020, North American Journal of Fisheries Management (40) 182-189
Management agencies are often charged with providing fisheries that lead to angler participation. Catch rate is one of the primary drivers of angler participation but can be influenced by a suite of factors, including population structure (e.g., density and size structure). The complexity of understanding how population structure influences angler...
Movement dynamics of Smallmouth Bass in a large western river system
Conor McClure, Michael C. Quist, Joseph Kozfkay, Michael Peterson, Daniel J. Schill
2020, North American Journal of Fisheries Management (40) 154-162
The Snake River, Idaho, between Swan Falls and Brownlee dams supports a popular fishery for Smallmouth Bass Micropterus dolomieu. Recently, anglers have expressed concern about harvest of Smallmouth Bass associated with seasonal congregations in and near the lower reaches of several major tributaries. Little is known about Smallmouth Bass movement in...
Overall results and key findings on the use of UAV visible-color, multispectral, and thermal infrared imagery to map agricultural drainage pipes
Barry J. Allred, Luis Martinez, Melake Fessehazion, Greg Rouse, Tanja N. Williamson, DeBonne Wishart, Triven Koganti, Robert Freeland, Neal Eash, Adam Batschelet, Robert Featheringill
2020, Agricultural Water Management (232)
Effective and efficient methods are needed to map agricultural subsurface drainage systems. Visible-color (VIS-C), multispectral (MS), and thermal infrared (TIR) imagery obtained by unmanned aerial vehicles (UAVs) may provide a means for determining drainage pipe locations. Aerial surveys using a UAV with VIS-C, MS, and TIR cameras were conducted at...
Eastern oyster clearance and respiration rates in response to acute and chronic exposure to suspended sediment loads
Megan K. La Peyre, S. K. Bernasconi, R. Lavaud, S. M. Casas, J. F. La Peyre
2020, Journal of Sea Research (157) 1-7
Coastal Louisiana supports some of the most productive areas for the eastern oyster, Crassostrea virginica. Changing conditions from restoration and climate change alter freshwater and sediment inflows into critical estuarine areas affecting water quality, including salinity and concentrations of suspended sediment. This study examined the effects of acute (1 h) and chronic (8 weeks) exposure of...
Infrasound generated by the 2016-2017 shallow submarine eruption of Bogoslof volcano, Alaska
John J. Lyons, Alexandra M. Iezzi, David Fee, Hans Schwaiger, Aaron Wech, Matthew M. Haney
2020, Bulletin of Volcanology (82)
The 2016–2017 shallow submarine eruption of Bogoslof volcano produced numerous infrasound signals over 9 months that were recorded on six Alaska Volcano Observatory (AVO) arrays at ranges of 59 to over 800 km from the volcano. The lack of geophysical monitoring near Bogoslof and the repeated production of volcanic clouds to flight...
SPEAR: The next generation GFDL modeling system for seasonal to multidecadal prediction and projection
Thomas L. Delworth, William F. Cooke, Alistair A. Adcroft, Mitchell Bushuk, Jan-Huey Chen, Krista A. Dunne, Paul Ginoux, Richard Gudgel, Lucas Harris, Matthew J. Harrison, Robert W. Hallberg, Nathaniel Johnson, Sarah B. Kapnick, Shian-Jian Lin, Feiyu Lu, Sergey Malyshev, Paul C. D. Milly, Hiroyuki Murakami, Vaishali Naik, Salvatore Pascale, David Paynter, Anthony Rosati, M. D. Schwarzkopf, Elena Shevliakova, Seth Underwood, Andrew T. Wittenberg, Baoqiang Xiang, Xiaosong Yang, Fanrong Zeng, Honghai Zhang, Liping Zhang, Ming Zhao
2020, Journal of Advances in Modeling Earth Systems (12)
We document the development and simulation characteristics of the next generation modeling system for seasonal to decadal prediction and projection at the Geophysical Fluid Dynamics Laboratory (GFDL). SPEAR (Seamless System for Prediction and EArth System Research) is built from component models recently developed at GFDL—the AM4 atmosphere model, MOM6 ocean...
A geospatially resolved wetland vulnerability index: Synthesis of physical drivers
Zafer Defne, Alfredo Aretxabaleta, Neil K. Ganju, Tarandeep S. Kalra, Daniel K. Jones, Kathryn E.L. Smith
2020, PLoS ONE (15)
Assessing wetland vulnerability to chronic and episodic physical drivers is fundamental for establishing restoration priorities. We synthesized multiple data sets from E.B Forsythe National Wildlife Refuge, New Jersey, to establish a wetland vulnerability metric that integrates a range of physical processes, regulatory information and physical/biophysical features. The geospatial data are based on aerial imagery,...
Multi-decadal patterns of vegetation succession after tundra fire on the Yukon-Kuskokwim Delta, Alaska
Gerald Frost, Rachel A. Loehman, Lisa Saperstein, Matthew J. Macander, Peter Nelson, David Paradis, Sue M. Natali
2020, Environmental Research Letters
Alaska’s Yukon-Kuskokwim Delta (YKD) is one of the warmest parts of the Arctic tundra biome and tundra fires are common in its upland areas. Here we combine field measurements, Landsat observations, and quantitative cover maps for tundra plant functional types (PFTs) to characterize multi-decadal succession and landscape change after fire in lichen-dominated upland tundra...
Climate relationships with increasing wildfire in the southwestern US from 1984 to 2015
Stephanie Mueller, Andrea E. Thode, Ellis Q. Margolis, Larissa Yocom, Jesse M. Young, Jose M. Iniguez
2020, Forest Ecology and Management (460)
Over the last several decades in forest and woodland ecosystems of the southwestern United States, wildfire size and severity have increased, thereby increasing the vulnerability of these systems to type conversions, invasive species, and other disturbances. A combination of land use history and climate change is widely thought to be...
Cyanotoxin occurrence in large rivers of the United States
Jennifer L. Graham, Neil Dubrovsky, Guy M. Foster, Lindsey R. King, Keith Loftin, Barry Rosen, Erin Stelzer
2020, Inland Waters (10) 109-117
Cyanotoxins occur in rivers worldwide but are understudied in lotic ecosystems relative to lakes and reservoirs. Eleven large river sites located throughout the United States were sampled during June–September 2017 to determine the occurrence of cyanobacteria with known cyanotoxin-producing strains, cyanotoxin synthetase genes, and cyanotoxins. Chlorophyll-a concentrations spanned the range...
Simulation modeling of complex climate, wildfire, and vegetation dynamics to address wicked problems in land management
Rachel A. Loehman, Robert E. Keane, Lisa M. Holsinger
2020, Frontiers in Forests and Global Change (3)
Complex, reciprocal interactions among climate, disturbance, and vegetation dramatically alter spatial landscape patterns and influence ecosystem dynamics. As climate and disturbance regimes shift, historical analogs and past empirical studies may not be entirely appropriate as templates for future management. The need for a better understanding of the potential impacts of climate changes on ecosystems...
Age distribution of red tree voles in northern spotted owl pellets estimated from molar tooth development
Chad A. Marks-Fife, Eric D. Forsman, Katie M. Dugger
2020, Northwest Science (93) 193-208
We used molar measurements from 136 known-age red tree voles (Arborimus longicaudus) to develop regression models that could estimate tree vole age from skeletonized remains. The best regression included a quadratic structure of the ratio between two measurements, crown height and anterior height, and natural log-transformed age in days. The...
Effects of temperature on hatching rate and early development of alligator gar and spotted gar in a laboratory setting
James M. Long, Richard A. Snow, M. J. Porta
2020, North American Journal of Fisheries Management (40) 661-668
Water temperature influences both morphological and physiological development in fishes. However, the effects of water temperature on the early development of Alligator Gar Atractosteus spatula and Spotted Gar Lepisosteus oculatus are not well understood. Both gar species were collected from natural environments and spawned in a hatchery setting. After spawning,...
How "simple" methodological decisions affect interpretation of population structure based on reduced representation library DNA sequencing: A case study using the lake whitefish
Carly F. Graham, Douglas R. Boreham, Richard G. Manzon, Wendylee Stott, Joanna Y. Wilson, Christopher M. Somers
2020, PLoS ONE (15)
Reduced representation (RRL) sequencing approaches (e.g., RADSeq, genotyping by sequencing) require decisions about how much to invest in genome coverage and sequencing depth, as well as choices of values for adjustable bioinformatics parameters. To empirically explore the importance of these “simple” methodological decisions, we generated two independent sequencing libraries for the same 142 individual...
