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...
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...
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...
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...
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...
A systematic approach towards the identification and protection of vulnerable marine ecosystems
Jeff A. Ardron, Malcolm R. Clark, Andrew J. Penney, Thomas F. Hourigan, Ashley A. Rowden, Piers K. Dunstan, Les Watling, Timothy M. Shank, Di M. Tracey, Matthew R. Dunn, Steven J. Parker
2014, Marine Science (49) 146-154
The United Nations General Assembly in 2006 and 2009 adopted resolutions that call for the identification and protection of vulnerable marine ecosystems (VMEs) from significant adverse impacts of bottom fishing. While general criteria have been produced, there are no guidelines or protocols that elaborate on the process from initial identification through to...
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...
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...
The spring migration of adult North American Ospreys
Mark S. Martell, Richard O. Bierregaard Jr., Brian E. Washburn, John E. Elliott, Charles J. Henny, Robert S. Kennedy, Iain MacLeod
2014, Journal of Raptor Research (48) 309-324
Most North American Ospreys (Pandion haliaetus) are migratory, breeding in northern latitudes and migrating long distances to and from their wintering grounds in the tropics. Although fall migration patterns of North American Ospreys have been described and studied, very little has been published about the spring migration of these birds....
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...
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...
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...
Predicting East African spring droughts using Pacific and Indian Ocean sea surface temperature indices
Christopher C. Funk, Andrew Hoell, Shraddhanand Shukla, Ileana Blade, Brant Liebmann, Jason B. Roberts, Franklin R. Robertson
2014, Hydrology and Earth System Sciences (11) 3111-3136
In southern Ethiopia, Eastern Kenya, and southern Somalia poor boreal spring rains in 1999, 2000, 2004, 2007, 2008, 2009 and 2011 contributed to severe food insecurity and high levels of malnutrition. Predicting rainfall deficits in this region on seasonal and decadal time frames can help decision makers support disaster risk...
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...
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...
Analysis of projected water availability with current basin management plan, Pajaro Valley, California
Randall T. Hanson, Brian Lockwood, Wolfgang Schmid
2014, Journal of Hydrology: Regional Studies (519) 131-147
The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement...
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,...
On-orbit performance of the Landsat 8 Operational Land Imager
Esad Micijevic, Kelly Vanderwerff, Pat Scaramuzza, Ron Morfitt, Julia A. Barsi, Raviv Levy
2014, Conference Paper, Proc. SPIE 9218, Earth Observing Systems XIX
The Landsat 8 satellite was launched on February 11, 2013, to systematically collect multispectral images for detection and quantitative analysis of changes on the Earth’s surface. The collected data are stored at the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center and continue the longest archive of...
Beyond reducing fire hazard: fuel treatment impacts on overstory tree survival
Brandon M. Collins, Adrian J. Das, John J. Battles, Danny L. Fry, Kevin Krasnow, Scott L. Stephens
2014, Ecological Applications (24) 1879-1886
Fuel treatment implementation in dry forest types throughout the western United States is likely to increase in pace and scale in response to increasing incidence of large wildfires. While it is clear that properly implemented fuel treatments are effective at reducing hazardous fire potential, there are ancillary ecological effects that...
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,...
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...
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...
