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Articles 1981 - 2010 of 4562

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Evaluating Methods To Establish Habitat Suitability Criteria: A Case Study In The Upper Delaware River Basin, Usa, H. S. Galbraith, C. J. Blakeslee, J. C. Cole, C. A. Talbert, K. O. Maloney Jan 2016

Evaluating Methods To Establish Habitat Suitability Criteria: A Case Study In The Upper Delaware River Basin, Usa, H. S. Galbraith, C. J. Blakeslee, J. C. Cole, C. A. Talbert, K. O. Maloney

United States Geological Survey: Staff Publications

Defining habitat suitability criteria (HSC) of aquatic biota can be a key component to environmental flow science. HSC can be developed through numerous methods; however, few studies have evaluated the consistency of HSC developed by different methodologies. We directly compared HSC for depth and velocity developed by the Delphi method (expert opinion) and by two primary literature meta-analyses (literature- derived range and interquartile range) to assess whether these independent methods produce analogous criteria for multiple species (rainbow trout, brown trout, American shad, and shallow fast guild) and life stages. We further evaluated how these two independently developed HSC affect calculations …


Evaluating Land Cover Influences On Model Uncertainties—A Case Study Of Cropland Carbon Dynamics In The Mid-Continent Intensive Campaign Region, Zhengpeng Li, Shuguang Liu, Xuesong Zhang, Tristram O. West, Stephen M. Ogle, Naijun Zhou Jan 2016

Evaluating Land Cover Influences On Model Uncertainties—A Case Study Of Cropland Carbon Dynamics In The Mid-Continent Intensive Campaign Region, Zhengpeng Li, Shuguang Liu, Xuesong Zhang, Tristram O. West, Stephen M. Ogle, Naijun Zhou

United States Geological Survey: Staff Publications

tQuantifying spatial and temporal patterns of carbon sources and sinks and their uncertainties acrossagriculture-dominated areas remains challenging for understanding regional carbon cycles. Character-istics of local land cover inputs could impact the regional carbon estimates but the effect has not beenfully evaluated in the past. Within the North American Carbon Program Mid-Continent Intensive (MCI)Campaign, three models were developed to estimate carbon fluxes on croplands: an inventory-basedmodel, the Environmental Policy Integrated Climate (EPIC) model, and the General Ensemble biogeo-chemical Modeling System (GEMS) model. They all provided estimates of three major carbon fluxes oncropland: net primary production (NPP), net ecosystem production (NEP), and …


Processes Contributing To Resilience Of Coastal Wetlands To Sea-Level Rise, Camille L. Stagg, Ken W. Krauss, Donald R. Cahoon, Nicole Cormier, William H. Conner, Christopher M. Swarzenski Jan 2016

Processes Contributing To Resilience Of Coastal Wetlands To Sea-Level Rise, Camille L. Stagg, Ken W. Krauss, Donald R. Cahoon, Nicole Cormier, William H. Conner, Christopher M. Swarzenski

United States Geological Survey: Staff Publications

The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising sea levels and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to sea-level rise along a transitional gradient from tidal freshwater forested wetland (TFFW) to marsh by measuring processes controlling wetland elevation. We found that, over 5 years of measurement, TFFWs were resilient, although some marginally, and oligohaline marshes exhibited robust resilience to sea-level rise. We identified fundamental differences in how resilience is maintained across wetland community types, …


Conserving California Condors In The 1980s, Noel F.R. Snyder Jan 2016

Conserving California Condors In The 1980s, Noel F.R. Snyder

United States Geological Survey: Staff Publications

By the late 1970s, the California condor (Gymnogyps californianus) was in serious trouble, with probably no more than about 30 birds left in existence, all in a mountainous region just north of Los Angeles that is vegetated mainly in chaparral and grasslands. All estimates of population size and trends offered since the early condor studies by Carl Koford in the 1930s and 1940s indicated a continuing decline toward extinction, and it appeared that few years were left before the species would be gone (see Koford, 1953; Wilbur, 1978). Evidently, the conservation steps that had been taken, including the …


Patuxent’S American Black Duck Studies From Chesapeake Bay To Maine And Beyond, Jerry R. Longcore Jan 2016

Patuxent’S American Black Duck Studies From Chesapeake Bay To Maine And Beyond, Jerry R. Longcore

United States Geological Survey: Staff Publications

The information in this chapter draws on published literature and unpublished reports written by staff members of the U.S. Geological Survey, Patuxent Wildlife Research Center (Patuxent), during its 75-year history. Reports by Bureau of Biological Survey (Biological Survey) and U.S. Fish and Wildlife Service (USFWS) personnel are included because the research entity currently known as Patuxent was formerly administered by these agencies. Some of the cited reports were prepared by USFWS scientists while they were not working at Patuxent. Literature resulting from work at other Federal and State agencies and private and academic institutions that influenced research at Patuxent on …


The Migratory Bird And Habitat Research Laboratory And The Accelerated Research Program, Richard A. Coon Jan 2016

The Migratory Bird And Habitat Research Laboratory And The Accelerated Research Program, Richard A. Coon

United States Geological Survey: Staff Publications

The Patuxent Wildlife Research Center (Patuxent) housed two important programs that were not supervised through the office of the Director of Patuxent during the 1960s and 1970s. Although they received administrative support from Patuxent, they were supervised from the U.S. Fish and Wildlife Service (USFWS) headquarters in Washington, D.C. One, the Migratory Bird Populations Station (MBPS), was established in 1961; the other, the Migratory Bird and Habitat Research Laboratory (MBHRL), was established in 1972 (Perry, 2004). This chapter briefly discusses MBPS and how some of its functions were transferred to MBHRL when this new laboratory was created.


Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove Jan 2016

Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove

United States Geological Survey: Staff Publications

Through laboratory and field studies, the utility of amino acid compound-specific nitrogen isotope analysis (AA-CSIA) in avian studies is investigated. Captive American kestrels (Falco sparverius) were fed an isotopically characterized diet and patterns in δ15N values of amino acids (AAs) were compared to those in their tissues (muscle and red blood cells) and food. Based upon nitrogen isotope discrimination between diet and kestrel tissues, AAs could mostly be categorized as source AAs (retaining baseline δ15N values) and trophic AAs (showing 15N enrichment). Trophic discrimination factors based upon the source (phenylalanine, Phe) and trophic (glutamic acid, Glu) AAs were 4.1 (muscle) …


Non-Linear Responses Of Glaciated Prairie Wetlands To Climate Warming, W. Carter Johnson, Brett Werner, Glenn R. Guntenspergen Jan 2016

Non-Linear Responses Of Glaciated Prairie Wetlands To Climate Warming, W. Carter Johnson, Brett Werner, Glenn R. Guntenspergen

United States Geological Survey: Staff Publications

The response of ecosystems to climate warming is likely to include threshold events when small changes in key environmental drivers produce large changes in an ecosystem. Wetlands of the Prairie Pothole Region (PPR) are especially sensitive to climate variability, yet the possibility that functional changes may occur more rapidly with warming than expected has not been examined or modeled. The productivity and biodiversity of these wetlands are strongly controlled by the speed and completeness of a vegetation cover cycle driven by the wet and dry extremes of climate. Two thresholds involving duration and depth of standing water must be exceeded …


Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman Jan 2016

Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman

United States Geological Survey: Staff Publications

The North American naturalist Constantine S. Rafinesque spent much of the year 1818 engaged in a solo journey down the Ohio River Valley to explore parts of what was then the western United States. Along the way, he visited a number of fellow naturalists, and he spent more than a week at the Henderson, Kentucky, home of artist and ornithologist John James Audubon. During the succeeding two years, Rafinesque published descriptions of new species that resulted from his expedition, including eleven species of fishes that eventually proved to have been invented by Audubon as a prank on the credulous naturalist. …


Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove Jan 2016

Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove

United States Geological Survey: Staff Publications

Through laboratory and field studies, the utility of amino acid compound-specific nitrogen isotope analysis (AA-CSIA) in avian studies is investigated. Captive American kestrels (Falco sparverius) were fed an isotopically characterized diet and patterns in δ15N values of amino acids (AAs) were compared to those in their tissues (muscle and red blood cells) and food. Based upon nitrogen isotope discrimination between diet and kestrel tissues, AAs could mostly be categorized as source AAs (retaining baseline δ15N values) and trophic AAs (showing 15N enrichment). Trophic discrimination factors based upon the source (phenylalanine, Phe) and trophic (glutamic acid, Glu) AAs were 4.1 (muscle) …


Non-Linear Responses Of Glaciated Prairie Wetlands To Climate Warming, W. Carter Johnson, Brett Werner, Glenn R. Guntenspergen Jan 2016

Non-Linear Responses Of Glaciated Prairie Wetlands To Climate Warming, W. Carter Johnson, Brett Werner, Glenn R. Guntenspergen

United States Geological Survey: Staff Publications

The response of ecosystems to climate warming is likely to include threshold events when small changes in key environmental drivers produce large changes in an ecosystem. Wetlands of the Prairie Pothole Region (PPR) are especially sensitive to climate variability, yet the possibility that functional changes may occur more rapidly with warming than expected has not been examined or modeled. The productivity and biodiversity of these wetlands are strongly controlled by the speed and completeness of a vegetation cover cycle driven by the wet and dry extremes of climate. Two thresholds involving duration and depth of standing water must be exceeded …


Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman Jan 2016

Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman

United States Geological Survey: Staff Publications

The North American naturalist Constantine S. Rafinesque spent much of the year 1818 engaged in a solo journey down the Ohio River Valley to explore parts of what was then the western United States. Along the way, he visited a number of fellow naturalists, and he spent more than a week at the Henderson, Kentucky, home of artist and ornithologist John James Audubon. During the succeeding two years, Rafinesque published descriptions of new species that resulted from his expedition, including eleven species of fishes that eventually proved to have been invented by Audubon as a prank on the credulous naturalist. …


Climate Change Mitigation, Technological Innovation And Adaptation: A New Perspective On Climate Policy, Michael J. Allen Jan 2016

Climate Change Mitigation, Technological Innovation And Adaptation: A New Perspective On Climate Policy, Michael J. Allen

Political Science & Geography Faculty Publications

The book Climate Change Mitigation, Technological Innovation and Adaptation outlines the complexities associated with addressing climate change including economic structure, technological innovation, and geopolitical willpower. By focusing on global economics, the text considers barriers to climate policy and future energy transformation away from carbon to more renewable sources. Additionally, the authors highlight the role of innovation in mitigation and adaptation.


Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk Jan 2016

Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk

Dartmouth Scholarship

Forests are more frequently being managed to store and sequester carbon for the purposes of climate change mitigation. Generally, this practice involves long-term conservation of intact mature forests and/or reductions in the frequency and intensity of timber harvests. However, incorporating the influence of forest surface albedo often suggests that long rotation lengths may not always be optimal in mitigating climate change in forests characterized by frequent snowfall. To address this, we investigated trade-offs between three ecosystem services: carbon storage, albedo-related radiative forcing, and timber provisioning. We calculated optimal rotation length at 498 diverse Forest Inventory and Analysis forest sites in …


Dynamic Ocean Management Increases The Efficiency And Efficacy Of Fisheries Management, Daniel C. Dunn, Sara M. Maxwell, Andre M. Boustany, Patrick N. Halpin Jan 2016

Dynamic Ocean Management Increases The Efficiency And Efficacy Of Fisheries Management, Daniel C. Dunn, Sara M. Maxwell, Andre M. Boustany, Patrick N. Halpin

Biological Sciences Faculty Publications

In response to the inherent dynamic nature of the oceans and continuing difficulty in managing ecosystem impacts of fisheries, interest in the concept of dynamic ocean management, or real-time management of ocean resources, has accelerated in the last several years. However, scientists have yet to quantitatively assess the efficiency of dynamic management over static management. Of particular interest is how scale influences effectiveness, both in terms of how it reflects underlying ecological processes and how this relates to potential efficiency gains. Here, we address the empirical evidence gap and further the ecological theory underpinning dynamic management. We illustrate, through the …


Positive Organizational Leadership And Pro-Environmental Behavior: The Phenomenon Of Institutional Fossil Fuel Divestment, Abigail Abrash Walton Jan 2016

Positive Organizational Leadership And Pro-Environmental Behavior: The Phenomenon Of Institutional Fossil Fuel Divestment, Abigail Abrash Walton

Antioch University Dissertations & Theses

Climate change is one of the most significant dynamics of our time.The predominant contributor to climate change is combustion of fossil fuels by humans.This study deepened understanding of organizational leaders’ role in enacting one approach to addressing climate change:institutional fossil fuel divestment.The study used a qualitative research design to explore U.S.-based foundation leaders’ readiness to pursue fossil fuel divestment by their institutions.The study examined leaders’ motivations and actions in pursuing divestment, while simultaneously exercising their fiduciary duty to steward institutional assets.Research questions focused on the divestment behavior change process and the outcomes of divestment on leaders and their organizations.Data collection …


Historical Processes And Contemporary Ocean Currents Drive Genetic Structure In The Seagrass Thalassia Hemprichii In The Indo-Australian Archipelago, Udhi E. Hernawan, Kor-Jent Van Dijk, Gary A. Kendrick, Ming Feng, Edward Biffin, Paul Lavery, Kathryn Mcmahon Jan 2016

Historical Processes And Contemporary Ocean Currents Drive Genetic Structure In The Seagrass Thalassia Hemprichii In The Indo-Australian Archipelago, Udhi E. Hernawan, Kor-Jent Van Dijk, Gary A. Kendrick, Ming Feng, Edward Biffin, Paul Lavery, Kathryn Mcmahon

Research Datasets

Understanding spatial patterns of gene flow and genetic structure is essential for the conservation of marine ecosystems. Contemporary ocean currents and historical isolation due to Pleistocene sea-level fluctuations have been predicted to influence the genetic structure in marine populations. In the Indo-Australian Archipelago (IAA), the world's hotspot of marine biodiversity, seagrasses are a vital component but population genetic information is very limited. Here, we reconstructed the phylogeography of the seagrass Thalassia hemprichii in the IAA based on single nucleotide polymorphisms (SNPs) and then characterised the genetic structure based on a panel of 16 microsatellite markers. We further examined the relative …


Key Biogeochemical Factors Affecting Soil Carbon Storage In Posidonia Meadows, Oscar Serrano, Aurora M. Ricart, Paul S. Lavery, Miguel-Angel Mateo, Ariane Arias-Ortiz, Pere Masque, Andy Steven, Carlos M. Duarte Jan 2016

Key Biogeochemical Factors Affecting Soil Carbon Storage In Posidonia Meadows, Oscar Serrano, Aurora M. Ricart, Paul S. Lavery, Miguel-Angel Mateo, Ariane Arias-Ortiz, Pere Masque, Andy Steven, Carlos M. Duarte

Research Datasets

The database compiles published data (in Serrano et al. 2015, Biogeosciences, doi:10.5194/bgd-12-18913-2015) on biogeochemical characteristics (age, density, organic carbon, inorganic carbon, stable carbon isotopes and sediment grain size) of sediments underneath seagrass meadows (Posidonia sinuosa) along a bathymetric gradient (from 2 to 8 m) and adjacent un-vegetated patches in Garden Island (Perth, Western Australia). The dataset compiles data on biogeochemical sediment characteristics (including organic and inorganic carbon stocks and burial rates) for a total of 5 cores (4 cores from seagrass meadows and 1 core from adjacent un-vegetated sediments).


Can Mud (Silt And Clay) Concentration Be Used To Predict Soil Organic Carbon Content Within Seagrass Ecosystems?, Oscar Serrano, Paul Lavery, Carlos M. Duarte, Gary A. Kendrick, Antoni Calafat, Paul York, Andy Steven, Peter Macreadie Jan 2016

Can Mud (Silt And Clay) Concentration Be Used To Predict Soil Organic Carbon Content Within Seagrass Ecosystems?, Oscar Serrano, Paul Lavery, Carlos M. Duarte, Gary A. Kendrick, Antoni Calafat, Paul York, Andy Steven, Peter Macreadie

Research Datasets

The database compiles published data (in Serrano et al. 2016, Biogeosciences, doi:10.5194/bg-2015-598) on biogeochemical characteristics (%organic carbon, stable carbon isotopes and mud content) of sediments underneath seagrass meadows and bare sediments in Australia and Spain. Details on habitat characteristics (latitude/longitude, water depth, seagrass species and geomorphology) and sediment depth are also provided for each location studied. The data set includes 1345 data entries from 100 sediment cores, encompassing 10 seagrass species in estuarine and coastal habitats.


Evaluating The Biogeochemical Functioning Of A Constructed Fen On The Post-Mining Landscape Of Athabasca Oil Sands Region, Fort Mcmurray, Alberta, Canada, Felix C. Nwaishi Jan 2016

Evaluating The Biogeochemical Functioning Of A Constructed Fen On The Post-Mining Landscape Of Athabasca Oil Sands Region, Fort Mcmurray, Alberta, Canada, Felix C. Nwaishi

Theses and Dissertations (Comprehensive)

Peatlands have a unique biogeochemical function, characterized by an imbalance between the rates of biomass accumulation and decomposition. These characteristics facilitate the ability of peatlands to support the sequestration of nutrients and carbon. In disturbed peatlands, these functions are compromised. Thus, reclamation targets amongst other key functions, the recovery of biogeochemical functioning. These functions could serve as a measure of recovery to conditions that are present in natural analogues. This thesis examines the recovery of microbially-mediated nutrient transformation processes in a fen peatland that was constructed on a post-mining landscape in the Athabasca oil sands region, Fort McMurray, Alberta. The …


Losing Ground, Alison Kanski Dec 2015

Losing Ground, Alison Kanski

Capstones

Climate change and sea level rise are slowly decimating beaches. But the U.S. government and loyal residents won't let go of the beaches so easily.

A determined resident of the Rockaways in New York fights for the money and attention from governments to sustain his lifelong home and stop it from washing away.


Odu, William & Mary Seek Funds For Joint Center On Sea-Level Rise, Dave Mayfield Dec 2015

Odu, William & Mary Seek Funds For Joint Center On Sea-Level Rise, Dave Mayfield

News Items

No abstract provided.


Three-Dimensional Wind Speed And Flux Measurements Over A Rain-Fed Soybean Field Using Orthogonal And Non-Orthogonal Sonic Anemometer Designs, Taylor Thomas Dec 2015

Three-Dimensional Wind Speed And Flux Measurements Over A Rain-Fed Soybean Field Using Orthogonal And Non-Orthogonal Sonic Anemometer Designs, Taylor Thomas

School of Natural Resources: Dissertations, Theses, and Student Research

The eddy covariance method for estimating fluxes of trace gases, energy and momentum in the constant flux layer above a plant canopy fundamentally relies on accurate measurements of the vertical wind speed. This wind speed is typically measured using a three-dimensional ultrasonic anemometer. Previous studies comparing anemometers with orthogonal transducer sets to those with non-orthogonal transducer sets suggest differences in measured 3D wind speed components, particularly for a vertical component. These differences, attributed to additional flow distortion caused by the non-orthogonal transducer arrangement and support structure, directly affect fluxes of trace gases, energy and momentum. A field experiment was conducted …


Development And Evaluation Of A Multi-Year Fractional Surface Water Data Set Derived From Active/Passive Microwave Remote Sensing Data, Ronny Schroeder, Kyle C. Mcdonald, Bruce D. Chapman, Katherine Jensen, Erika Podest, Zachary D. Tessler, Theodore J. Bohn, Reiner Zimmermann Dec 2015

Development And Evaluation Of A Multi-Year Fractional Surface Water Data Set Derived From Active/Passive Microwave Remote Sensing Data, Ronny Schroeder, Kyle C. Mcdonald, Bruce D. Chapman, Katherine Jensen, Erika Podest, Zachary D. Tessler, Theodore J. Bohn, Reiner Zimmermann

Publications and Research

The sensitivity of Earth’s wetlands to observed shifts in global precipitation and temperature patterns and their ability to produce large quantities of methane gas are key global change questions. We present a microwave satellite-based approach for mapping fractional surface water (FW) globally at 25-km resolution. The approach employs a land cover-supported, atmospherically-corrected dynamic mixture model applied to 20+ years (1992–2013) of combined, daily, passive/active microwave remote sensing data. The resulting product, known as Surface WAter Microwave Product Series (SWAMPS), shows strong microwave sensitivity to sub-grid scale open water and inundated wetlands comprising open plant canopies. SWAMPS’ FW compares favorably (R2 …


Why Add Edible And Floral Plants To Riparian Forest Buffers? Dec 2015

Why Add Edible And Floral Plants To Riparian Forest Buffers?

Working Trees (USDA-NAC)

Why add edible and floral plants to riparian forest buffers?

Multifunctional riparian forest buffers (MRFBs) offer the opportunity to produce perennial crops of native fruits and nuts, as well as floral trees and shrubs.


Umphlett Qci 2015, Natalie A. Umphlett Dec 2015

Umphlett Qci 2015, Natalie A. Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Late Hard Freeze

Late Freezes Extended Growing Season

Warm Fall Delays Bird Migrations

Monitoring Water Resources Across the Basin

3-Month Precipitation and Temperature Outlooks


Evaluation Of Large‑Scale Meteorological Patterns Associated With Temperature Extremes In The Narccap Regional Climate Model Simulations, Paul C. Loikith, Duane E. Waliser, Huikyo Lee, J. David Neelin, Benjamin Lintner, Seth Mcginnis, Linda Mears, Jinwon Kim Dec 2015

Evaluation Of Large‑Scale Meteorological Patterns Associated With Temperature Extremes In The Narccap Regional Climate Model Simulations, Paul C. Loikith, Duane E. Waliser, Huikyo Lee, J. David Neelin, Benjamin Lintner, Seth Mcginnis, Linda Mears, Jinwon Kim

Geography Faculty Publications and Presentations

Large-scale meteorological patterns (LSMPs) associated with temperature extremes are evaluated in a suite of regional climate model (RCM) simulations contributing to the North American Regional Climate Change Assessment Program. LSMPs are characterized through composites of surface air temperature, sea level pressure, and 500 hPa geopotential height anomalies concurrent with extreme temperature days. Six of the seventeen RCM simulations are driven by boundary conditions from reanalysis while the other eleven are driven by one of four global climate models (GCMs). Four illustrative case studies are analyzed in detail. Model fidelity in LSMP spatial representation is high for cold winter extremes near …


Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar Dec 2015

Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar

Graduate Theses and Dissertations

Energy security through increased biofuel production is one of the components of the Energy Independence and Security Act (EISA) 2007. As per EISA 2007 mandate, appropriate independent research institutes are required to assess concerns to natural biodiversity due to biofuel production and report it to the Congress through the Environment Protection Agency (EPA). Planners, researchers, and agencies concerned with environmental regulations, ideally, would like to have location-specific information about the impacts for developing appropriate management interventions. This study examines long-term impacts on water quality in response to targeted (i.e. marginal lands) production of biofuel crops by setting up two SWAT …


Macrobenthic Communities In The Northern Gulf Of Mexico Hypoxic Zone: Testing The Pearson-Rosenberg Model, Shivakumar Shivarudrappa Dec 2015

Macrobenthic Communities In The Northern Gulf Of Mexico Hypoxic Zone: Testing The Pearson-Rosenberg Model, Shivakumar Shivarudrappa

Dissertations

The Pearson and Rosenberg (P-R) conceptual model of macrobenthic succession was used to assess the impact of hypoxia (dissolved oxygen [DO] ≤ 2 mg/L) on the macrobenthic community on the continental shelf of northern Gulf of Mexico for the first time. The model uses a stress-response relationship between environmental parameters and the macrobenthic community to determine the ecological condition of the benthic habitat. The ecological significance of dissolved oxygen in a benthic habitat is well understood. In addition, the annual recurrence of bottom-water hypoxia on the Louisiana/Texas shelf during summer months is well documented.

The P-R model illustrates the decreasing …


Modifying A Cow-Calf Biophysical Simulation Model For Analyses Of Alternative Enterprises, Jennifer L. Lutes Dec 2015

Modifying A Cow-Calf Biophysical Simulation Model For Analyses Of Alternative Enterprises, Jennifer L. Lutes

Graduate Theses and Dissertations

Cow-calf producers in the United States, tasked with providing beef calves for the beef industry, have had a multitude of difficulties to overcome in recent years. Producers in northwest Arkansas were negatively impacted by high hay prices coupled with low beef cattle market prices due to severe drought experienced in portions of 2010, 2011, and 2012. During this time they also faced high grain prices, due to a record low harvest, combined with portions of the corn harvest diverted from human and animal feed to ethanol production. Tight lending policies of this time, reminiscent of the housing market crash in …