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Page 1283, results 32051 - 32075

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Last interglacial plant macrofossils and climates from Ziegler Reservoir, Snowmass Village, Colorado, USA
Laura E. Strickland, Richard G. Baker, Robert S. Thompson, Dane M. Miller
2014, Quaternary Research (82) 553-566
Ninety plant macrofossil taxa from the Ziegler Reservoir fossil site near Snowmass Village, Colorado, record environmental changes at high elevation (2705 m asl) in the Rocky Mountains during the Last Interglacial Period. Present-day vegetation is aspen forest (Populus tremuloides) intermixed with species of higher (Picea, Abies) and lower (Artemisia, Quercus) elevations. Stratigraphic units 4–13...
Efficacy of plastic mesh tubes in reducing herbivory damage by the invasive nutria (Myocastor coypus) in an urban restoration site
Trevor R. Sheffels, Mark D. Systma, Jacoby Carter, Jimmy D. Taylor
2014, Northwest Science (88) 269-279
The restoration of stream corridors is becoming an increasingly important component of urban landscape planning, and the high cost of these projects necessitates the need to understand and address potential ecological obstacles to project success. The nutria(Myocastor coypus) is an invasive, semi-aquatic rodent native to South America that causes detrimental ecological...
A sub-national scale geospatial analysis of diamond deposit lootability: the case of the Central African Republic
Katherine C. Malpeli, Peter G. Chirico
2014, The Extractive Industries and Society (1) 249-259
The Central African Republic (CAR), a country with rich diamond deposits and a tumultuous political history, experienced a government takeover by the Seleka rebel coalition in 2013. It is within this context that we developed and implemented a geospatial approach for assessing the lootability of high value-to-weight resource deposits, using...
Influence of nonnative and native ungulate biomass and seasonal precipitation on vegetation production in a Great Basin ecosystem
Linda Zeigenfuss, Kathryn A. Schoenecker, Jason I. Ransom, Drew A. Ignizio, Tracy Mask
2014, Western North American Naturalist (74) 286-298
The negative effects of equid grazers in semiarid ecosystems of the American West have been considered disproportionate to the influence of native ungulates in these systems because of equids' large body size, hoof shape, and short history on the landscape relative to native ungulates. Tools that can analyze the degree...
A suggestion for computing objective function in model calibration
Yiping Wu, Shuguang Liu
2014, Ecological Informatics (24) 107-111
A parameter-optimization process (model calibration) is usually required for numerical model applications, which involves the use of an objective function to determine the model cost (model-data errors). The sum of square errors (SSR) has been widely adopted as the objective function in various optimization procedures. However, ‘square error’ calculation was...
Evaluation of a model framework to estimate soil and soil organic carbon redistribution by water and tillage using 137Cs in two U.S. Midwest agricultural fields
Claudia J. Young, Shuguang Liu, Joseph A. Schumacher, Thomas E. Schumacher, Thomas C. Kaspar, Gregory W. McCarty, Darrell Napton, Dan B. Jaynes
2014, Geoderma (232-234) 437-448
Cultivated lands in the U.S. Midwest have been affected by soil erosion, causing soil organic carbon (SOC) redistribution in the landscape and other environmental and agricultural problems. The importance of SOC redistribution on soil productivity and crop yield, however, is still uncertain. In this study, we used a model framework,...
Understanding the hydrologic sources and sinks in the Nile Basin using multisource climate and remote sensing data sets
Gabriel B. Senay, Naga Manohar Velpuri, Stefanie Bohms, Yonas Demissie, Mekonnen Gebremichael
2014, Water Resources Research (50) 8625-8650
In this study, we integrated satellite-drived precipitation and modeled evapotranspiration data (2000–2012) to describe spatial variability of hydrologic sources and sinks in the Nile Basin. Over 2000–2012 period, 4 out of 11 countries (Ethiopia, Tanzania, Kenya, and Uganda) in the Nile Basin showed a positive water balance while three downstream...
Predicting probability of occurrence and factors affecting distribution and abundance of three Ozark endemic crayfish species at multiple spatial scales
Matthew S. Nolen, Daniel D. Magoulick, Robert J. DiStefano, Emily M. Imhoff, Brian K. Wagner
2014, Freshwater Biology (59) 2374-2389
Crayfishes and other freshwater aquatic fauna are particularly at risk globally due to anthropogenic demand, manipulation and exploitation of freshwater resources and yet are often understudied. The Ozark faunal region of Missouri and Arkansas harbours a high level of aquatic biological diversity, especially in regard to endemic crayfishes....
A cross comparison of spatiotemporally enhanced springtime phenological measurements from satellites and ground in a northern U.S. mixed forest
Li Li, Mark D. Schwartz, Zhuosen Wang, Feng Gao, Crystal B. Schaaf, Bin Tan, Jeffrey T. Morisette, Xiaoyang Zhang
2014, IEEE Transactions on Geoscience and Remote Sensing (52) 7513-7526
Cross comparison of satellite-derived land surface phenology (LSP) and ground measurements is useful to ensure the relevance of detected seasonal vegetation change to the underlying biophysical processes. While standard 16-day and 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index (VI)-based springtime LSP has been evaluated in previous studies, it remains...
Distribution and prevalence of knemidokoptic mange in Hawai`i `Amakihi on the island of Hawaii
Jacqueline Gaudioso, Dennis LaPointe, Carter T. Atkinson, Chloe Apelgren
2014, Technical Report HCSU-055
Knemidokoptic mange was first observed on two Hawai‘i ‘Amakihi (Hemignathus virens) mist netted in Manuka Natural Area Reserve (NAR) on the Island of Hawai‘i in June 2007. Microscopic examination of skin scrapings from lesions of the infested individuals revealed the scaley-leg mite, Knemidokoptes jamaicensis. Continued surveillance at Manuka NAR (2007-2009)...
Holocene earthquakes and right-lateral slip on the left-lateral Darrington-Devils Mountain fault zone, northern Puget Sound, Washington
Stephen F. Personius, Richard W. Briggs, Alan R. Nelson, Elizabeth R Schermer, J. Zebulon Maharrey, Brian L. Sherrod, Sarah A. Spaulding, Lee-Ann Bradley
2014, Geosphere (10) 1482-1500
Sources of seismic hazard in the Puget Sound region of northwestern Washington include deep earthquakes associated with the Cascadia subduction zone, and shallow earthquakes associated with some of the numerous crustal (upper-plate) faults that crisscross the region. Our paleoseismic investigations on one of the more prominent crustal faults, the Darrington–Devils...
Towards understanding the puzzling lack of acid geothermal springs in Tibet (China): Insight from a comparison with Yellowstone (USA) and some active volcanic hydrothermal systems
D. Kirk Nordstrom, Qinghai Guo, R. Blaine McCleskey
2014, Journal of Volcanology and Geothermal Research (288) 94-104
Explanations for the lack of acid geothermal springs in Tibet are inferred from a comprehensive hydrochemical comparison of Tibetan geothermal waters with those discharged from Yellowstone (USA) and two active volcanic areas, Nevado del Ruiz (Colombia) and Miravalles (Costa Rica) where acid springs are widely distributed and diversified in terms...
Transcriptomic analysis of the mussel Elliptio complanata identifies candidate stress-response genes and an abundance of novel or noncoding transcripts
Robert S. Cornman, Laura S. Robertson, Heather S. Galbraith, Carrie J. Blakeslee
2014, PLoS ONE (9)
Mussels are useful indicator species of environmental stress and degradation, and the global decline in freshwater mussel diversity and abundance is of conservation concern. Elliptio complanata is a common freshwater mussel of eastern North America that can serve both as an indicator and as an experimental model for understanding mussel...
Demographics of piscivorous colonial waterbirds and management implications for ESA-listed salmonids on the Columbia Plateau
Jessica Y. Adkins, Donald E. Lyons, Peter J. Loschl, Daniel D. Roby, Ken Collis, Allen F. Evans, Nathan J. Hostetter
2014, Northwest Science (88) 344-359
We investigated colony size, productivity, and limiting factors for five piscivorous waterbird species nesting at 18 locations on the Columbia Plateau (Washington) during 2004–2010 with emphasis on species with a history of salmonid (Oncorhynchus spp.) depredation. Numbers of nesting Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus) were stable at...
A legacy of divergent fishery management regimes and the resilience of rainbow and cutthroat trout populations in Lake Crescent, Olympic National Park, Washington
Samuel J. Brenkman, Jeffrey J. Duda, Philip R. Kennedy, Bruce M. Baker
2014, Northwest Science (88) 280-304
As a means to increase visitation, early fisheries management in the National Park Service (NPS) promoted sport harvest and hatchery supplementation. Today, NPS management objectives focus on the preservation of native fish. We summarized management regimes of Olympic National Park's Lake Crescent, which included decades of liberal sport harvest and...
Relationships between annual plant productivity, nitrogen deposition and fire size in low-elevation California desert scrub
Leela E. Rao, John R. Matchett, Matthew L. Brooks, Robert Johns, Richard A. Minnich, Edith B. Allen
2014, International Journal of Wildland Fire (24) 48-58
Although precipitation is correlated with fire size in desert ecosystems and is typically used as an indirect surrogate for fine fuel load, a direct link between fine fuel biomass and fire size has not been established. In addition, nitrogen (N) deposition can affect fire risk through its fertilisation effect on...
Prevalence of the amphibian chytrid fungus (Batrachochytrium dendrobatidis) at Buenos Aires National Wildlife Refuge, Arizona, USA
Brent H. Sigafus, Blake R. Hossack, Erin L. Muths, Cecil R. Schwalbe
2014, Herpetological Review (45) 41-42
Information on disease presence can be of use to natural resource managers, especially in areas supporting threatened and endangered species that occur coincidentally with species that are suspected vectors for disease. Ad hoc reports may be of limited utility (Muths et al. 2009), but a general sense of pathogen presence...
Factors influencing nest survival and productivity of Red-throated Loons (Gavia stellata) in Alaska
Daniel Rizzolo, Joel A. Schmutz, Sarah E. McCloskey, Thomas F. Fondell
2014, The Condor (116) 574-587
Red-throated Loon (Gavia stellata) numbers in Alaska have fluctuated dramatically over the past 3 decades; however, the demographic processes contributing to these population dynamics are poorly understood. To examine spatial and temporal variation in productivity, we estimated breeding parameters at 5 sites in Alaska: at Cape Espenberg and the Copper...
Technical Note: Linking climate change and downed woody debris decomposition across forests of the eastern United States
Matthew B. Russell, Christopher W. Woodall, Anthony W. D’Amato, Shawn Fraver, John B. Bradford
2014, Biogeosciences (11) 6417-6425
Forest ecosystems play a critical role in mitigating greenhouse gas emissions. Forest carbon (C) is stored through photosynthesis and released via decomposition and combustion. Relative to C fixation in biomass, much less is known about C depletion through decomposition of woody debris, particularly under a changing climate. It is assumed...
Productivity of forest birds at Hakalau Forest NWR
Eben H. Paxton, George C Cummins, Steven J. Kendall
2014, Technical Report HCSU-056
Hawai‘i has some of the most endangered avian species in the world, which face numerous threats from habitat loss, disease, climate change, and introduced species. This report details the results of a two-year productivity study of all forest bird species at Hakalau National Wildlife Refuge, Hawai‘i Island. We found and...
Evaluating potential effects of an industrial road on winter habitat of caribou in North-Central Alaska
Ryan H. Wilson, David D. Gustine, Kyle Joly
2014, Arctic (67) 472-482
Worldwide, some caribou (Rangifer tarandus) populations are experiencing declines due partially to the expansion of industrial development. Caribou can exhibit behavioral avoidance of development, leading to indirect habitat loss, even if the actual footprint is small. Thus, it is important to understand before construction begins how much habitat might be...
Diverse coral communities in mangrove habitats suggest a novel refuge from climate change
Kimberly K. Yates, Caroline S. Rogers, James J. Herlan, Gregg R. Brooks, Nathan A. Smiley, Rebekka A. Larson
2014, Biogeosciences (11) 4321-4337
Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business-as-usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH,...
Population viability of Pediocactus brady (Cactaceae) in a changing climate
Daniel F. Shryock, Todd C. Esque, Lee Huges
2014, American Journal of Botany (101) 1944-1953
• Premise of the study: A key question concerns the vulnerability of desert species adapted to harsh, variable climates to future climate change. Evaluating this requires coupling long-term demographic models with information on past and projected future climates. We investigated climatic drivers of population growth using a 22-yr demographic model for Pediocactus bradyi,...
Effects of prey abundance, distribution, visual contrast and morphology on selection by a pelagic piscivore
Adam G. Hansen, David A. Beauchamp
2014, Freshwater Biology (59) 2328-2341
Most predators eat only a subset of possible prey. However, studies evaluating diet selection rarely measure prey availability in a manner that accounts for temporal–spatial overlap with predators, the sensory mechanisms employed to detect prey, and constraints on prey capture.We evaluated the diet selection of cutthroat trout...
The fungus Trichophyton redellii sp. nov. causes skin infections that resemble white-nose syndrome of hibernating bats
Jeffrey M. Lorch, Andrew M. Minnis, Carol U. Meteyer, Jennifer A. Redell, J. Paul White, Heather M. Kaarakka, Laura K. Muller, David L. Lindner, Michelle L. Verant, Valerie I. Shearn-Bochsler, David S. Blehert
2014, Journal of Wildlife Diseases (51) 36-47
Before the discovery of white-nose syndrome (WNS), a fungal disease caused by Pseudogymnoascus destructans, there were no reports of fungal skin infections in bats during hibernation. In 2011, bats with grossly visible fungal skin infections similar in appearance to WNS were reported from multiple sites in Wisconsin, USA, a state outside...