Effects of model layer simplification using composite hydraulic properties
Nicasio Sepulveda, Eve L. Kuniansky
2010, Hydrogeology Journal (18) 405-416
The effects of simplifying hydraulic property layering within an unconfined aquifer and the underlying confining unit were assessed. The hydraulic properties of lithologic units within the unconfined aquifer and confining unit were computed by analyzing the aquifer-test data using radial, axisymmetric two-dimensional (2D) flow. Time-varying recharge to the unconfined aquifer...
A Natural Resource Condition Assessment for Rocky Mountain National Park
D.M. Theobald, Jill Baron, P. Newman, B. Noon, J. B. Norman III, I. Leinwand, S.E. Linn, R. Sherer, K.E. Williams, M. Hartman
2010, Report
We conducted a natural resource assessment of Rocky Mountain National Park (ROMO) to provide a synthesis of existing scientific data and knowledge to address the current conditions for a subset of important park natural resources. The intent is for this report to help provide park resource managers with data and...
Impact of harvest on survival of a heavily hunted game bird population
Virginie Rolland, J. A. Hostetler, Tommy C. Hines, H. Franklin Percival, Madan K. Oli
2010, Wildlife Research (37) 392-400
Context. Despite their economic importance and intensive management, many game bird species, including the northern bobwhite Colinus virginianus, are in decline. Declines may be explained, at least in part, by low survival due perhaps to poor habitat quality, high predation or excessive hunting pressure.Aims. This study sought to estimate and...
Persistent organic pollutants in the blood of free-ranging sea otters (Enhydra lutris ssp.) in Alaska and California
David A. Jessup, Christine K. Johnson, James Estes, Daphne Carlson-Bremer, Walter M. Jarman, Stacey Reese, Erin Dodd, M. T. Tinker, Michael H. Ziccardi
2010, Journal of Wildlife Diseases (46) 1214-1233
As part of tagging and ecologic research efforts in 1997 and 1998, apparently healthy sea otters of four age-sex classes in six locations in Alaska and three in California were sampled for persistent organic pollutants (POPs) and other chemicals of ecologic or environmental concern (COECs). Published techniques for the detection...
3D volumetric modeling of grapevine biomass using Tripod LiDAR
K.E. Keightley, G.W. Bawden
2010, Computers and Electronics in Agriculture (74) 305-312
Tripod mounted laser scanning provides the means to generate high-resolution volumetric measures of vegetation structure and perennial woody tissue for the calculation of standing biomass in agronomic and natural ecosystems. Other than costly destructive harvest methods, no technique exists to rapidly and accurately measure above-ground perennial tissue for woody plants...
Multi-species occurrence models to evaluate the effects of conservation and management actions
E.F. Zipkin, Royle J. Andrew, D.K. Dawson, S. Bates
2010, Biological Conservation (143) 479-484
Conservation and management actions often have direct and indirect effects on a wide range of species. As such, it is important to evaluate the impacts that such actions may have on both target and non-target species within a region. Understanding how species richness and composition differ as a result of...
Sediment transport under wave groups: Relative importance between nonlinear waveshape and nonlinear boundary layer streaming
X. Yu, T.-J. Hsu, D.M. Hanes
2010, Journal of Geophysical Research C: Oceans (115)
Sediment transport under nonlinear waves in a predominately sheet flow condition is investigated using a two-phase model. Specifically, we study the relative importance between the nonlinear waveshape and nonlinear boundary layer streaming on cross-shore sand transport. Terms in the governing equations because of the nonlinear boundary layer process are included...
A late Miocene-early Pliocene chain of lakes fed by the Colorado River: Evidence from Sr, C, and O isotopes of the Bouse Formation and related units between Grand Canyon and the Gulf of California
J. A. Roskowski, P. J. Patchett, J.E. Spencer, P. A. Pearthree, D. L. Dettman, J. E. Faulds, A. C. Reynolds
2010, Geological Society of America Bulletin (122) 1625-1636
We report strontium isotopic results for the late Miocene Hualapai Limestone of the Lake Mead area (Arizona-Nevada) and the latest Miocene to early Pliocene Bouse Formation and related units of the lower Colorado River trough (Arizona-California-Nevada), together with parallel oxygen and carbon isotopic analyses of Bouse samples, to constrain the...
Association of wintering raptors with Conservation Reserve Enhancement Program grasslands in Pennsylvania
A. Wilson, M. Brittingham, G. Grove
2010, Journal of Field Ornithology (81) 361-372
Conservation grasslands can provide valuable habitat resource for breeding songbirds, but their value for wintering raptors has received little attention. We hypothesized that increased availability of grassland habitat through the Conservation Reserve Enhancement Program (CREP) has resulted in an increase or redistribution in numbers of four species of raptors in...
Climatic water deficit, tree species ranges, and climate change in Yosemite National Park
James A. Lutz, Jan W. Van Wagtendonk, Jerry F. Franklin
2010, Journal of Biogeography (37) 936-350
Aim (1) To calculate annual potential evapotranspiration (PET), actual evapotranspiration (AET) and climatic water deficit (Deficit) with high spatial resolution; (2) to describe distributions for 17 tree species over a 2300-m elevation gradient in a 3000-km2 landscape relative to AET and Deficit; (3) to examine changes in AET and Deficit...
Linking ecosystems, food webs, and fish production: subsidies in salmonid watersheds
Mark S. Wipfli, Colden V. Baxter
2010, Fisheries (35) 373-387
Physical characteristics of riverine habitats, such as large wood abundance, pool geometry and abundance, riparian vegetation cover, and surface flow conditions, have traditionally been thought to constrain fish production in these ecosystems. Conversely, the role of food resources (quantity and quality) in controlling fish production has received far less attention...
Effects of prior detections on estimates of detection probability, abundance, and occupancy
Jason D. Riddle, Rua S. Mordecai, Kenneth H. Pollock, Theodore R. Simons
2010, The Auk (127) 94-99
Survey methods that account for detection probability often require repeated detections of individual birds or repeated visits to a site to conduct Counts or collect presence-absence data. Initial encounters with individual species or individuals of a species could influence detection probabilities for subsequent encounters. For example, observers may be more...
Design and analysis of simple choice surveys for natural resource management
John Fieberg, Louis Cornicelli, David C. Fulton, Marrett D. Grund
2010, Journal of Wildlife Management (74) 871-879
We used a simple yet powerful method for judging public support for management actions from randomized surveys. We asked respondents to rank choices (representing management regulations under consideration) according to their preference, and we then used discrete choice models to estimate probability of choosing among options (conditional on the set...
Development of a macrophyte-based index of biotic integrity for Minnesota lakes
M.W. Beck, L.K. Hatch, B. Vondracek, R.D. Valley
2010, Ecological Indicators (10) 968-979
Traditional approaches for managing aquatic resources have often failed to account for effects of anthropogenic disturbances on biota that are not directly reflected by chemical and physical proxies of environmental condition. The index of biotic integrity (IBI) is a potentially effective assessment method to integrate ecological, functional, and structural aspects...
Relevance of risk predictions derived from a chronic species sensitivity distribution with cadmium to aquatic populations and ecosystems
C.A. Mebane
2010, Risk Analysis (30) 203-223
Criteria to protect aquatic life are intended to protect diverse ecosystems, but in practice are usually developed from compilations of single-species toxicity tests using standard test organisms that were tested in laboratory environments. Species sensitivity distributions (SSDs) developed from these compilations are extrapolated to set aquatic ecosystem criteria. The protectiveness...
Treated wastewater and Nitrate transport beneath irrigated fields near Dodge city, Kansas
M. Sophocleous, M.A. Townsend, F. Vocasek, Liwang Ma, K.C. Ashok
2010, Current Research in Earth Sciences (258) 1-31
Use of secondary-treated municipal wastewater for crop irrigation south of Dodge City, Kansas, where the soils are mainly of silty clay loam texture, has raised a concern that it has resulted in high nitratenitrogen concentrations (10-50 mg/kg) in the soil and deeper vadose zone, and also in the underlying deep...
Evaluating the spatiotemporal variations of water budget across China over 1951-2006 using IBIS model
Q. Zhu, H. Jiang, J. Liu, X. Wei, C. Peng, X. Fang, S. Liu, G. Zhou, S. Yu, W. Ju
2010, Hydrological Processes (24) 429-445
The Integrated Biosphere Simulator is used to evaluate the spatial and temporal patterns of the crucial hydrological variables [run-off and actual evapotranspiration (AET)] of the water balance across China for the period 1951–2006 including a precipitation analysis. Results suggest three major findings. First, simulated run-off captured 85% of the spatial...
The spatial and temporal variability of groundwater recharge in a forested basin in northern Wisconsin
W. R. Dripps, K. R. Bradbury
2010, Hydrological Processes (24) 383-392
Recharge varies spatially and temporally as it depends on a wide variety of factors (e.g. vegetation, precipitation, climate, topography, geology, and soil type), making it one of the most difficult, complex, and uncertain hydrologic parameters to quantify. Despite its inherent variability, groundwater modellers, planners, and policy makers often ignore recharge...
Seasonal groundwater contribution to crop-water use assessed with lysimeter observations and model simulations
Y. Luo, M. Sophocleous
2010, Journal of Hydrology (389) 325-335
Groundwater evaporation can play an important role in crop-water use where the water table is shallow. Lysimeters are often used to quantify the groundwater evaporation contribution influenced by a broad range of environmental factors. However, it is difficult for such field facilities, which are operated under limited conditions within limited...
A shallow subsurface controlled release facility in Bozeman, Montana, USA, for testing near surface CO2 detection techniques and transport models
L.H. Spangler, L.M. Dobeck, K.S. Repasky, A.R. Nehrir, S.D. Humphries, C.J. Keith, J.A. Shaw, J.H. Rouse, A.B. Cunningham, S.M. Benson, C.M. Oldenburg, J.L. Lewicki, A.W. Wells, J.R. Diehl, B.R. Strazisar, J.E. Fessenden, T.A. Rahn, J.E. Amonette, J.L. Barr, W.L. Pickles, J.D. Jacobson, E. A. Silver, E.J. Male, H.W. Rauch, K.S. Gullickson, R. Trautz, Yousif K. Kharaka, J. Birkholzer, L. Wielopolski
2010, Environmental Earth Sciences (60) 227-239
A controlled field pilot has been developed in Bozeman, Montana, USA, to study near surface CO2 transport and detection technologies. A slotted horizontal well divided into six zones was installed in the shallow subsurface. The scale and CO2 release rates were chosen to be relevant to developing monitoring strategies for...
Valuing ecosystem services from wetlands restoration in the Mississippi Alluvial Valley
W.A. Jenkins, B. C. Murray, R.A. Kramer, S.P. Faulkner
2010, Ecological Economics (69) 1051-1061
This study assesses the value of restoring forested wetlands via the U.S. government's Wetlands Reserve Program (WRP) in the Mississippi Alluvial Valley by quantifying and monetizing ecosystem services. The three focal services are greenhouse gas (GHG) mitigation, nitrogen mitigation, and waterfowl recreation. Site- and region-level measurements of these ecosystem services...
Modern climate challenges and the geological record
Thomas M. Cronin
2010, American Paleontologist (18) 10-12
Today's changing climate poses challenges about the influence of human activity, such as greenhouse gas emissions and land use changes, the natural variability of Earth's climate, and complex feedback processes. Ice core and instrumental records show that over the last century, atmospheric carbon dioxide (CO2) concentrations have risen to 390...
Challenges in merging fisheries research and management: The Upper Mississippi River experience
J. Garvey, B. Ickes, S. Zigler
2010, Hydrobiologia (640) 125-144
The Upper Mississippi River System (UMRS) is a geographically diverse basin extending 10?? north temperate latitude that has produced fishes for humans for millennia. During European colonization through the present, the UMRS has been modified to meet multiple demands such as navigation and flood control. Invasive species, notably the common...
Headwater streams and forest management: does ecoregional context influence logging effects on benthic communities?
R. Bruce Medhurst, Mark S. Wipfli, Chris Binckley, Karl Polivka, Paul F. Hessburg, R. Brion Salter
2010, Hydrobiologia (641) 71-83
Effects of forest management on stream communities have been widely documented, but the role that climate plays in the disturbance outcomes is not understood. In order to determine whether the effect of disturbance from forest management on headwater stream communities varies by climate, we evaluated benthic macroinvertebrate communities in 24...
Monitoring on-orbit calibration stability of the Terra MODIS and Landsat 7 ETM+ sensors using pseudo-invariant test sites
G. Chander, X. Xiong, T. Choi, A. Angal
2010, Remote Sensing of Environment (114) 925-939
The ability to detect and quantify changes in the Earth's environment depends on sensors that can provide calibrated, consistent measurements of the Earth's surface features through time. A critical step in this process is to put image data from different sensors onto a common radiometric scale. This work focuses on...
