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...
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...
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,...
Estimates of natural salinity and hydrology in a subtropical estuarine ecosystem: implications for Greater Everglades restoration
Frank E. Marshall, G. Lynn Wingard, Patrick A. Pitts
2014, Estuaries and Coasts (37) 1449-1466
Disruption of the natural patterns of freshwater flow into estuarine ecosystems occurred in many locations around the world beginning in the twentieth century. To effectively restore these systems, establishing a pre-alteration perspective allows managers to develop science-based restoration targets for salinity and hydrology. This paper describes a process to develop...
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,...
Feeding habits of an endemic fish, Oxygymnocypris stewartii, in the Yarlung Zangbo River in Tibet, China
Bin Huo, Cong Xin Xie, Charles P. Madenjian, Bao Shan Ma, Xue Feng Yang, Hai Ping Huang
2014, Environmental Biology of Fishes (97) 1279-1293
Feeding habits of Oxygymnocypris stewartii were investigated based on monthly sampling in the Yarlung Zangbo River from August 2008 to August 2009. The gut contents of 194 individuals were analysed and quantified with numerical and gravimetric methods. This species can be considered a generalized and opportunistic predator feeding both on teleosts...
Understanding the hydrologic sources and sinks in the Nile Basin using multisource climate and remote sensing data sets
Gabriel 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...
Identifying hazards associated with lava deltas
Michael P. Poland, Tim R. Orr
2014, Bulletin of Volcanology (76)
Lava deltas, formed where lava enters the ocean and builds a shelf of new land extending from the coastline, represent a significant local hazard, especially on populated ocean island volcanoes. Such structures are unstable and prone to collapse—events that are often accompanied by small explosions that can deposit boulders and...
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...
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....
Environmental stressors afflicting tailwater stream reaches across the United States
Leandro E. Miranda, R. M. Krogman
2014, River Research and Applications (30) 1184-1194
The tailwater is the reach of a stream immediately below an impoundment that is hydrologically, physicochemically and biologically altered by the presence and operation of a dam. The overall goal of this study was to gain a nationwide awareness of the issues afflicting tailwater reaches in the United States. Specific...
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...
Does lake size matter? Combining morphology and process modeling to examine the contribution of lake classes to population-scale processes
Luke A. Winslow, Jordan S. Read, Paul C. Hanson, Emily H. Stanley
2014, Inland Waters (5) 7-14
With lake abundances in the thousands to millions, creating an intuitive understanding of the distribution of morphology and processes in lakes is challenging. To improve researchers’ understanding of large-scale lake processes, we developed a parsimonious mathematical model based on the Pareto distribution to describe the distribution of lake morphology (area,...
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,...
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)...
Costs and benefits of group living with disease: a case study of pneumonia in bighorn lambs (Ovis canadensis)
Kezia R. Manlove, E. Frances Cassirer, Paul C. Cross, Raina K. Plowright, Peter J. Hudson
2014, Proceedings of the Royal Society B (281)
Group living facilitates pathogen transmission among social hosts, yet temporally stable host social organizations can actually limit transmission of some pathogens. When there are few between-subpopulation contacts for the duration of a disease event, transmission becomes localized to subpopulations. The number of per capita infectious contacts approaches the subpopulation size as pathogen...
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...
A seasonal agricultural drought forecast system for food-insecure regions of East Africa
Shraddhanand Shukla, Amy McNally, Gregory Husak, Christopher C. Funk
2014, Hydrology and Earth System Sciences (11) 3049-3081
The increasing food and water demands of East Africa's growing population are stressing the region's inconsistent water resources and rain-fed agriculture. More accurate seasonal agricultural drought forecasts for this region can inform better water and agricultural management decisions, support optimal allocation of the region's water resources, and mitigate socio-economic losses...
Energy demands for maintenance, growth, pregnancy, and lactation of female Pacific walruses (Odobenus rosmarus divergens)
Shawn R. Noren, Mark S. Udevitz, Chadwick V. Jay
2014, Physiological and Biochemical Zoology (87) 837-854
Decreases in sea ice have altered habitat use and activity patterns of female Pacific walruses Odobenus rosmarus divergens and could affect their energetic demands, reproductive success, and population status. However, a lack of physiological data from walruses has hampered efforts to develop the bioenergetics models required for fully understanding potential...
The impact of static stress change, dynamic stress change, and the background stress on aftershock focal mechanisms
Jeanne L. Hardebeck
2014, Journal of Geophysical Research B: Solid Earth (119) 8239-8266
The focal mechanisms of earthquakes in Southern California before and after four M ≥ 6.7 main shocks provide insight into how fault systems respond to stress and changes in stress. The main shock static stress changes have two observed impacts on the seismicity: changing the focal mechanisms in a given location to favor...
Aquifers of Arkansas: protection, management, and hydrologic and geochemical characteristics of groundwater resources in Arkansas
Timothy M. Kresse, Phillip D. Hays, Katherine R. Merriman, Jonathan A. Gillip, D. Todd Fugitt, Jane L. Spellman, Anna M. Nottmeier, Drew A. Westerman, Joshua M. Blackstock, James L. Battreal
2014, Scientific Investigations Report 2014-5149
Sixteen aquifers in Arkansas that currently serve or have served as sources of water supply are described with respect to existing groundwater protection and management programs, geology, hydrologic characteristics, water use, water levels, deductive analysis, projections of hydrologic conditions, and water quality. State and Federal protection and management programs are...
Status of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, 2012 to 2014
Cristi V. Hansen, Joshua A. Whisnant, Jennifer L. Lanning-Rush
2014, Scientific Investigations Report 2014-5185
Development of the Wichita well field in the Equus Beds aquifer in southwest Harvey County and northwest Sedgwick County began in the 1940s to supply water to the city of Wichita. The decline of water levels in the Equus Beds aquifer was noted soon after the development of the Wichita...
Geologic framework for the national assessment of carbon dioxide storage resources: Williston Basin, Central Montana Basins, and Montana Thrust Belt study areas
Marc L. Buursink, Matthew D. Merrill, William H. Craddock, Tina L. Roberts-Ashby, Sean T. Brennan, Madalyn S. Blondes, P.A. Freeman, Steven M. Cahan, Christina A. DeVera, Celeste D. Lohr
Peter D. Warwick, M.D. Corum, editor(s)
2014, Open-File Report 2012-1024-J
The 2007 Energy Independence and Security Act directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used by the USGS for the national CO2 assessment follows that of previous USGS work. This methodology is non-economic and is...
Groundwater-flow and land-subsidence model of Antelope Valley, California
Adam J. Siade, Tracy Nishikawa, Diane L. Rewis, Peter Martin, Steven P. Phillips
2014, Scientific Investigations Report 2014-5166
Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley groundwater basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to...
A geologic and mineral exploration spatial database for the Stillwater Complex, Montana
Michael L. Zientek, Heather L. Parks
2014, Scientific Investigations Report 2014-5183
The Stillwater Complex is a Neoarchean, ultramafic to mafic layered intrusion exposed in the Beartooth Mountains in south-central Montana. This igneous intrusion contains magmatic mineralization that is variably enriched in strategic and critical commodities such as chromium, nickel, and the platinum-group elements. One deposit, the J-M Reef, is the sole...
