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Environmental Sciences

2014

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Articles 31 - 60 of 586

Full-Text Articles in Life Sciences

An Introduction To Sheep, Debra K. Aaron, Donald G. Ely Dec 2014

An Introduction To Sheep, Debra K. Aaron, Donald G. Ely

Agriculture and Natural Resources Publications

The information in this fact sheet was developed to provide a quick reference to the most frequently asked questions about sheep and sheep production.


Basic Sheep Genetics, Debra K. Aaron Dec 2014

Basic Sheep Genetics, Debra K. Aaron

Agriculture and Natural Resources Publications

Genetics is the science of heredity. It seeks to explain differences and similarities exhibited by related individuals. The application of genetics to livestock improvement is known as animal breeding. The objective of this fact sheet is to provide a refresher course on basic genetics and to show how knowledge of genetics can be used to improve sheep production.


Keeping And Using Flock Performance Records, Debra K. Aaron Dec 2014

Keeping And Using Flock Performance Records, Debra K. Aaron

Agriculture and Natural Resources Publications

Performance records serve as the cornerstone of any good livestock management program. Unfortunately, the task of collecting, maintaining and using performance records is the one area of livestock production in general that gets the least attention. This fact sheet provides ten reasons why all sheep producers need to keep performance records on their flocks. Then, some ways of maintaining and using those records are discussed.


Sheep Breeding: Heritability, Ebvs, Epds And The Nsip, Debra K. Aaron Dec 2014

Sheep Breeding: Heritability, Ebvs, Epds And The Nsip, Debra K. Aaron

Agriculture and Natural Resources Publications

Genetic improvement in a flock depends on the producer’s ability to select breeding sheep that are genetically superior for traits of economic importance. This is complicated by the fact that an animal’s own performance is not always a true indicator of its genetic potential as a parent.


Inbreeding In Sheep, Debra K. Aaron Dec 2014

Inbreeding In Sheep, Debra K. Aaron

Agriculture and Natural Resources Publications

Inbreeding is broadly defined as the mating of individuals that are related. Strictly speaking, however, all animals within a breed are related. So, in a sense, every purebred sheep producer practices some degree of inbreeding. In most cases this relationship is very slight. Therefore, inbreeding is more practically defined as the mating of individuals more closely related than the average of the breed. This practice includes mating brother to sister, sire to daughter and son to dam.


Crossbreeding Considerations In Sheep, Debra K. Aaron Dec 2014

Crossbreeding Considerations In Sheep, Debra K. Aaron

Agriculture and Natural Resources Publications

Crossbreeding is the mating of individuals from different breeds. To a certain extent, it is a simple concept, but embarking upon a crossbreeding program, in sheep or any other livestock species, involves long-term decisions.

The primary benefits of a crossbreeding program are heterosis and breed complementarity.


2015-2016 Burley And Dark Tobacco Production Guide, Robert C. Pearce, William A. Bailey, Lowell P. Bush, Jonathan D. Green, Anne M. Jack, Robert D. Miller, William M. Snell, Lee H. Townsend, Mark A. Purschwitz, Larry D. Swetnam, John H. Wilhoit, Eric Walker, Steve Bost, Neil Rhodes, David Reed, Chuck Johnson, Loren Fisher, Matthew Vann, Scot Whitley, Mina Mila Dec 2014

2015-2016 Burley And Dark Tobacco Production Guide, Robert C. Pearce, William A. Bailey, Lowell P. Bush, Jonathan D. Green, Anne M. Jack, Robert D. Miller, William M. Snell, Lee H. Townsend, Mark A. Purschwitz, Larry D. Swetnam, John H. Wilhoit, Eric Walker, Steve Bost, Neil Rhodes, David Reed, Chuck Johnson, Loren Fisher, Matthew Vann, Scot Whitley, Mina Mila

Agriculture and Natural Resources Publications

Burley and dark tobacco growers in the U.S. make hundreds of decisions every growing season that impact the yield and quality of the crops that they produce. These decisions may include choosing appropriate varieties, planning effective pest control measures or perhaps deciding the best time to top or harvest a crop. Increasingly, tobacco growers are being required by the industry to record and justify their management decisions and actions. The most comprehensive example of this is the U.S. Tobacco Good Agricultural Practices (GAP) program that was initiated during the 2013 growing season and expanded in ...


The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown Dec 2014

The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown

Papers in Natural Resources

Episodes of food deprivation may change how nestling birds allocate energy to the growth of skeletal and feather morphological traits during development. Cliff swallows (Petrochelidon pyrrhonota) are colonial, insectivorous birds that regu­larly experience brief periods of severe weather–induced food deprivation during the nesting season which may affect offspring development. We investigated how annual variation in timing of rearing and weather were associated with length of wing and tail, skeletal traits, and body mass in juvenile cliff swallows reared in southwestern Nebraska during 2001–2006. As predicted under conditions of food deprivation, nestling skeletal and feather measurements were generally ...


Groundwater Trend Analysis And Salinity Risk Assessment For The South-West Agricultural Region Of Western Australia, 2007–12, G Paul Raper, Russell Speed, John Andrew Simons, A L. Killen, Andrew Blake, A T. Ryder, Rosemary H. Smith, Grant Stainer, L Bourke Dec 2014

Groundwater Trend Analysis And Salinity Risk Assessment For The South-West Agricultural Region Of Western Australia, 2007–12, G Paul Raper, Russell Speed, John Andrew Simons, A L. Killen, Andrew Blake, A T. Ryder, Rosemary H. Smith, Grant Stainer, L Bourke

Resource management technical reports

Dryland salinity is a hydrologically driven land degradation hazard in the south-west agricultural region of Western Australia (WA). Shallow-rooted annual crops and pastures transpire significantly less water than the native vegetation they replaced, leading to an increase in recharge, rising groundwater levels and the development of shallow watertables in areas where often none existed previously. Rising groundwater levels mobilise soluble salts, naturally stored at high concentrations in the regolith. These salts can be concentrated in the root zone of vegetation by evapotranspiration.


Fire Induced Reproductive Mechanisms Of A Symphoricarpos (Caprifoliaceae) Shrub After Dormant Season Burning, John Derek Scasta, David M. Engle, Ryan N. Harr, Diane M. Debinski Dec 2014

Fire Induced Reproductive Mechanisms Of A Symphoricarpos (Caprifoliaceae) Shrub After Dormant Season Burning, John Derek Scasta, David M. Engle, Ryan N. Harr, Diane M. Debinski

Ecology, Evolution and Organismal Biology Publications

Background: Symphoricarpos, a genus of the Caprifoliaceae family, consists of about 15 species of clonal deciduous shrubs in North America and 1 species endemic to China. In North American tallgrass prairie, Symphoricarpos orbiculatus (buckbrush) is the dominant shrub often forming large colonies via sexual and asexual reproductive mechanisms. Symphoricarpos shrubs, in particular S. orbiculatus, use a unique sexual reproductive mechanism known as layering where vertical stems droop and the tips root upon contact with the soil. Because of conflicting societal values of S. orbiculatus for conservation and agriculture and the current attempt to restore historical fire regimes, there is a ...


Comparison Of Cellulosic Ethanol Yields From Midwestern Maize And Reconstructed Tallgrass Prairie Systems Managed For Bioenergy, V. A. Nichols, F. E. Miguez, M. E. Jarchow, M. Z. Liebman, B. S. Dien Dec 2014

Comparison Of Cellulosic Ethanol Yields From Midwestern Maize And Reconstructed Tallgrass Prairie Systems Managed For Bioenergy, V. A. Nichols, F. E. Miguez, M. E. Jarchow, M. Z. Liebman, B. S. Dien

Agronomy Publications

Maize- and prairie-based systems were investigated as cellulosic feedstocks by conducting a 9 ha side-by-side comparison on fertile soils in the Midwestern United States. Maize was grown continuously with adequate fertilization over years both with and without a winter rye cover crop, and the 31-species reconstructed prairie was grown with and without spring nitrogen fertilization. Both maize stover and prairie biomass were harvested in the fall. We compared amounts of cellulosic biomass produced and harvested, carbohydrate contents as measured by both dietary and detergent methods, and estimated cellulosic ethanol yields per hectare. From 2009–2013, the cropping system with the ...


Biomass Burning Fuel Consumption Rates: A Field Measurement Database, T. T. Van Leeuwen, G. R. Van Der Werf, A. A. Hoffmann, R. G. Detmers, G. Rücker, Nancy H. F. French, S. Archibald, J. A. Carvalho Jr, G. D. Cook, William J. De Groot, C. Hély, Eric S. Kasischke, S. Kloster, Jessica Mccarty, M. L. Pettinari, P. Savadogo, E. C. Alvarado, L. Boschetti, S. Manuri, C. P. Meyer, F. Siegert, L. A. Trollope, W. S. W. Trollope Dec 2014

Biomass Burning Fuel Consumption Rates: A Field Measurement Database, T. T. Van Leeuwen, G. R. Van Der Werf, A. A. Hoffmann, R. G. Detmers, G. Rücker, Nancy H. F. French, S. Archibald, J. A. Carvalho Jr, G. D. Cook, William J. De Groot, C. Hély, Eric S. Kasischke, S. Kloster, Jessica Mccarty, M. L. Pettinari, P. Savadogo, E. C. Alvarado, L. Boschetti, S. Manuri, C. P. Meyer, F. Siegert, L. A. Trollope, W. S. W. Trollope

Michigan Tech Research Institute Publications

Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. Fuel consumption (FC) depends on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions. While burned area can be detected from space and estimates are becoming more reliable due to improved algorithms and sensors, FC is usually modeled or taken selectively from the literature. We compiled the peer-reviewed literature on FC for various biomes and fuel categories to understand FC and its variability better, and ...


Reproductive Success Of The American Oystercatcher (Haematopus Palliatus) In Texas, Lianne M. Koczur, Alexandra E. Munters, Susan A. Heath, Bart M. Ballard, M. Clay Green, Stephen J. Dinsmore, Fidel Hernández Dec 2014

Reproductive Success Of The American Oystercatcher (Haematopus Palliatus) In Texas, Lianne M. Koczur, Alexandra E. Munters, Susan A. Heath, Bart M. Ballard, M. Clay Green, Stephen J. Dinsmore, Fidel Hernández

Natural Resource Ecology and Management Publications

The American Oystercatcher (Haematopus palliatus) is listed as a Species of High Concern in the United States Shorebird Conservation Plan due to a small population size and threats during its annual cycle. Previous studies of the American Oystercatcher have focused on Atlantic Coast populations; however, little is known about the reproductive success of the western Gulf Coast population. The objective of this study was to determine nest and brood survival of American Oystercatchers in Texas. A total of 337 nests and 121 broods were monitored on the Texas Gulf Coast during 2011–2013. The top model for nest survival in ...


Reconstructing Vegetation Past: Pre-Euro-American Vegetation For The Midwest Driftless Area, Usa, Monika E. Shea, Lisa A. Schulte, Brian J. Palik Dec 2014

Reconstructing Vegetation Past: Pre-Euro-American Vegetation For The Midwest Driftless Area, Usa, Monika E. Shea, Lisa A. Schulte, Brian J. Palik

Natural Resource Ecology and Management Publications

Historical reference conditions provide important context for creating ecological restoration and management plans. The U.S. 19th Century Public Land Survey (PLS) records provide extensive ecological information for constructing such reference conditions. We used PLS records to reconstruct pre-Euro-American tree species cover class and vegetation structure types for the Midwest Driftless Area, a 55,000 km2 region currently experiencing multiple conservation threats. We related cover classes to soil texture, topographic roughness, and distance from waterway. Our analyses revealed that the landscape of the Driftless Area was mostly composed of savanna, with two large patches of closed forest and smaller, scattered ...


Automated Lidar-Derived Canopy Height Estimates For The Upper Mississippi River System, Enrika Hlavacek Dec 2014

Automated Lidar-Derived Canopy Height Estimates For The Upper Mississippi River System, Enrika Hlavacek

MS GIS Program Major Individual Projects

Land cover/land use (LCU) classifications serve as important decision support products for researchers and land managers. The LCU classifications produced by the U.S. Geological Survey’s Upper Midwest Environmental Sciences Center (UMESC) include canopy height estimates that are assigned through manual aerial photography interpretation techniques. In an effort to improve upon these techniques, this project investigated the use of high-density lidar data for the Upper Mississippi River System to determine canopy height. An ArcGIS tool was developed to automatically derive height modifier information based on the extent of land cover features for forest classes. The measurement of canopy ...


Satellite-Based Management Tool For Oak Savanna Ecosystem Restoration, Peter T. Wolter, Elizabeth A. Berkley, Scott D. Peckham, Aditya Singh Dec 2014

Satellite-Based Management Tool For Oak Savanna Ecosystem Restoration, Peter T. Wolter, Elizabeth A. Berkley, Scott D. Peckham, Aditya Singh

Natural Resource Ecology and Management Publications

The structure and function of oak Quercus spp. savanna ecosystems in the North American Midwest were originally maintained by an active disturbance regime (often fire). Subsequent reductions in the frequency of disturbance after European settlement have facilitated rapid, regional conversion of these ecosystems to more closed-canopy forest. Hence, regional-scale management strategies are now needed to restore critical spatial gradients of light, temperature, soil moisture, and soil organic matter for recovery and sustenance of the unique mosaic of understory grass and forb species assemblages that define oak savannas. Tree species composition, distribution, mortality, basal area, and canopy cover are important forest ...


Interactive Effects Of Climate Change With Nutrients, Mercury, And Freshwater Acidification On Key Taxa In The North Atlantic Landscape Conservation Cooperative Region, Alfred E. Pinkey, Charles T. Driscoll, David C. Evers, Michael J. Hooper, Jeffrey Horan, Jess W. Jones, Rebecca S. Lazarus, Harold G. Marshall, Andrew Milliken, Barnett A. Rattner, John Schmerfold, Donald W. Sparling Dec 2014

Interactive Effects Of Climate Change With Nutrients, Mercury, And Freshwater Acidification On Key Taxa In The North Atlantic Landscape Conservation Cooperative Region, Alfred E. Pinkey, Charles T. Driscoll, David C. Evers, Michael J. Hooper, Jeffrey Horan, Jess W. Jones, Rebecca S. Lazarus, Harold G. Marshall, Andrew Milliken, Barnett A. Rattner, John Schmerfold, Donald W. Sparling

Biological Sciences Faculty Publications

The North Atlantic Landscape Conservation Cooperative LCC (NA LCC) is a public-private partnership that provides information to support conservation decisions that may be affected by global climate change (GCC) and other threats. The NA LCC region extends from southeast Virginia to the Canadian Maritime Provinces. Within this region, the US National Climate Assessment documented increases in air temperature, total precipitation, frequency of heavy precipitation events, and rising sea level, and predicted more drastic changes. Here, we synthesize literature on the effects of GCC interacting with selected contaminant, nutrient, and environmental processes to adversely affect natural resources within this region. Using ...


Gis For The Bartlett Hills Association: Increasing Knowledge To Enhance Land Management Practices, Stephanie R. Sattler Dec 2014

Gis For The Bartlett Hills Association: Increasing Knowledge To Enhance Land Management Practices, Stephanie R. Sattler

MS GIS Program Major Individual Projects

The natural world has many unique areas and when there is no management conducted on these areas, they become lost to time. The 800-acre property owned by the Bartlett Hills Association (BHA) in western Iowa is no different. The loess hills are deposits from glaciers 12,000 to 30,000 years ago, and over the last several decades there has been no management of these unique hills on the property. The BHA has established management objectives that will bring its forest back to a sustainable forest and its members want to use GIS to enhance their knowledge. There are currently ...


Decontamination Protocols For Watercraft And Wildland Firefighting Equipment In Preventing The Spread Of Invasive Quagga (Dreissena Rostriformis Bugensis) And Zebra (Dreissena Polymorpha) Mussels, Ashlie Watters Dec 2014

Decontamination Protocols For Watercraft And Wildland Firefighting Equipment In Preventing The Spread Of Invasive Quagga (Dreissena Rostriformis Bugensis) And Zebra (Dreissena Polymorpha) Mussels, Ashlie Watters

UNLV Theses, Dissertations, Professional Papers, and Capstones

Quagga and zebra mussels (Dreissena rostriformis bugensis and Dreissena polymorpha) are two invasive species introduced via ballast water discharged by large oceanic cargo ships to the North American Great Lakes in the late 1980s. Once established, the mussels spread quickly. In January 2007, D. rostriformis bugensis was discovered in Lake Mead, NV-AZ, and in that same year, mussels were confirmed further south on the Colorado River in Lakes Mojave and Havasu. Dreissenids clog water intake pipes, water filtration systems, and electric generating plants. The mussels also ruin boat motors, damage recreational equipment, and once established in the reservoir, routine maintenance ...


River Health In Puyo, Ecuador The Use Of Macroinvertebrates As Bioindicators Of Water Quality And Alternatives To Chlorine For Whitening Clothes In The Puyo River Watershed, Allison Rowe Dec 2014

River Health In Puyo, Ecuador The Use Of Macroinvertebrates As Bioindicators Of Water Quality And Alternatives To Chlorine For Whitening Clothes In The Puyo River Watershed, Allison Rowe

Independent Study Project (ISP) Collection

Fresh water is an important resource in Puyo, Ecuador, a city named after the Kichwa word for ‘cloudy’ in reference to its overcast weather. However, the Puyo River watershed is the most contaminated in all of Pastaza Province. The objective of this investigation was first to evaluate the health of the Puyo River using macroinvertebrate analyses and measurements of chlorine concentrations, temperature, pH, turbidity, velocity, and flow rate. The second objective was to learn about practices used to whiten clothes in Puyo and perceptions of water quality in order to understand the magnitude of bleach pollution and the population’s ...


The North American Carbon Program Multi-Scale Synthesis And Terrestrial Model Intercomparison Project – Part 2: Environmental Driver Data, Y. Wei, S. Liu, D. N. Huntzinger, A. M. Michalak, N. Viovy, W. M. Post, C. R. Schwalm, K. Schaefer, A. R. Jacobson, Chaoqun (Crystal) Lu, Hanqin Tian, D. M. Ricciuto, R. B. Cook, J. Mao, X. Shi Dec 2014

The North American Carbon Program Multi-Scale Synthesis And Terrestrial Model Intercomparison Project – Part 2: Environmental Driver Data, Y. Wei, S. Liu, D. N. Huntzinger, A. M. Michalak, N. Viovy, W. M. Post, C. R. Schwalm, K. Schaefer, A. R. Jacobson, Chaoqun (Crystal) Lu, Hanqin Tian, D. M. Ricciuto, R. B. Cook, J. Mao, X. Shi

Chaoqun (Crystal) Lu

Ecosystems are important and dynamic components of the global carbon cycle, and terrestrial biospheric models (TBMs) are crucial tools in further understanding of how terrestrial carbon is stored and exchanged with the atmosphere across a variety of spatial and temporal scales. Improving TBM skills, and quantifying and reducing their estimation uncertainties, pose significant challenges. The Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) is a formal multi-scale and multi-model intercomparison effort set up to tackle these challenges. The MsTMIP protocol prescribes standardized environmental driver data that are shared among model teams to facilitate model–model and model–observation comparisons. This ...


Switchgrass Cultivar, Harvest Frequency, Fertilizer Source, And Irrigation Effects On Near-Surface Soil Properties In West-Central Arkansas, Alayna A. Jacobs Dec 2014

Switchgrass Cultivar, Harvest Frequency, Fertilizer Source, And Irrigation Effects On Near-Surface Soil Properties In West-Central Arkansas, Alayna A. Jacobs

Theses and Dissertations

Switchgrass (Panicum virgatum L.) has been identified as a model bioenergy feedstock crop and is expected to become an important feedstock for future renewable fuel generation. Agronomic management combinations that maximize monoculture switchgrass yield are generally well understood; however, little is known about corresponding effects of differing switchgrass management combinations on near-surface soil properties. The objective of this research was to determine the residual near-surface soil property effects of three years (2008 to 2011) of consistent management combinations to maximize switchgrass biomass production, including cultivar (‘Alamo’ and ‘Cave-in-Rock’), harvest frequency (1-cut and 2-cut systems per year), fertilizer source (poultry litter ...


Citizen Science Reveals Widespread Negative Effects Of Roads On Amphibian Distributions, Bradley J. Cosentino, David M. Marsh, Kara S. Jones, Joseph J. Apodaca, Christopher Bates, Jessica Beach, Karen H. Beard, Kelsie Becklin, Jane Margaret Bell, Christopher Crockett, George Fawson, Jennifer Fjelsted, Elizabeth A. Forys, Kristen S. Genet, Melanie Grover, Jaimie Holmes, Katherine Indeck, Nancy E. Karraker, Eran S. Kilpatrick, Tom A. Langen, Stephen G. Mugel, Alessandro Molina, James R. Vonesh, Ryan J. Weaver, Anisha Willey Dec 2014

Citizen Science Reveals Widespread Negative Effects Of Roads On Amphibian Distributions, Bradley J. Cosentino, David M. Marsh, Kara S. Jones, Joseph J. Apodaca, Christopher Bates, Jessica Beach, Karen H. Beard, Kelsie Becklin, Jane Margaret Bell, Christopher Crockett, George Fawson, Jennifer Fjelsted, Elizabeth A. Forys, Kristen S. Genet, Melanie Grover, Jaimie Holmes, Katherine Indeck, Nancy E. Karraker, Eran S. Kilpatrick, Tom A. Langen, Stephen G. Mugel, Alessandro Molina, James R. Vonesh, Ryan J. Weaver, Anisha Willey

Wildland Resources Faculty Publications

Landscape structure is important for shaping the abundance and distribution of amphibians, but prior studies of landscape effects have been species or ecosystem-specific. Using a large-scale, citizen science-generated database, we examined the effects of habitat composition, road disturbance, and habitat split (i.e. the isolation of wetland from forest by intervening land use) on the distribution and richness of frogs and toads in the eastern and central United States. Undergraduates from nine biology and environmental science courses collated occupancy data and characterized landscape structure at 1617 sampling locations from the North American Amphibian Monitoring Program. Our analysis revealed that anuran ...


A Social–Ecological Systems Approach To Non-Native Species: Habituation And Its Effect On Management Of Coqui Frogs In Hawaii, Emily A. Kalnicky, Mark W. Brunson, Karen H. Beard Dec 2014

A Social–Ecological Systems Approach To Non-Native Species: Habituation And Its Effect On Management Of Coqui Frogs In Hawaii, Emily A. Kalnicky, Mark W. Brunson, Karen H. Beard

Wildland Resources Faculty Publications

Non-native species introductions have the ability to affect both ecological and social systems, thus to address those outcomes both ecological and social influences on an invasion need to be understood. We use a social–ecological systems approach to investigate connections between human and ecological factors that affect efforts to control the non-native coqui frog (Eleutherodactylus coqui) on the island of Hawaii. The coqui frog is recognized as a ‘pest’ and ‘injurious wildlife’ by the Hawaii Department of Agriculture. Because the coqui occurs on many small private properties across the island, it is necessary to enlist private citizens in control efforts ...


Book Review Of Conservation By Proxy: Indicator, Umbrella, Keystone, Flagship, And Other Surrogate Species, Tyler J. Grant, Peter G. Eyheralde, Melissa S. C. Telemeco, Amy L. Moorhouse, Rebecca A. Reeves, Karin Grimlund, Amy Podaril, Sarah E. Emeterio, Robert W. Klaver Dec 2014

Book Review Of Conservation By Proxy: Indicator, Umbrella, Keystone, Flagship, And Other Surrogate Species, Tyler J. Grant, Peter G. Eyheralde, Melissa S. C. Telemeco, Amy L. Moorhouse, Rebecca A. Reeves, Karin Grimlund, Amy Podaril, Sarah E. Emeterio, Robert W. Klaver

Natural Resource Ecology and Management Publications

In the tallgrass prairies of the United States, the regal fritillary (Speyeria idalia) often is considered a reliable indicator of high quality remnant habitat. Purple milkweed (Asclepias purpurascens) is considered an indicator of high quality oak savanna habitat at the edge of prairie. Indicator and other surrogate species often are regarded as inescapable necessities in conservation, because limited budgets and the myriad pieces of an ecosystem render comprehensive monitoring impossible. Regardless of whether or not surrogate species are necessary, do they really work?


The Response Of Cotton (Gossypium Hirsutum L.) To Slow Release Foliar Fertilization And The Effect Of Environment On Absorption, James Matthews Burke Dec 2014

The Response Of Cotton (Gossypium Hirsutum L.) To Slow Release Foliar Fertilization And The Effect Of Environment On Absorption, James Matthews Burke

Theses and Dissertations

In cotton production, nitrogen (N) is the most limiting nutrient and the demand is substantial. Foliar-N fertilization is regarded as an effective and environmentally sound method of supplying cotton with N during times of deficiency and high demand. In response to the potential benefits of the foliar-N fertilization of cotton, a myriad of foliar-N based fertilizers have been created; each with their own individual chemical technology and constitution. Experiments were performed with the objectives of examining the effects of the slow-release foliar-N fertilizer, Nitamin® (1) on the growth and development of field-grown cotton, (2) on uptake under various environmental conditions ...


Recruitment Facilitation And Spatial Pattern Formation In Soft-Bottom Mussel Beds, John A. Commito, Ann E. Commito, Rutherford V. Platt, Benjamin M. Grupe, Wendy Dow Piniak, Natasha J. Gownaris, Kyle A. Reeves, Allison M. Vissichelli Dec 2014

Recruitment Facilitation And Spatial Pattern Formation In Soft-Bottom Mussel Beds, John A. Commito, Ann E. Commito, Rutherford V. Platt, Benjamin M. Grupe, Wendy Dow Piniak, Natasha J. Gownaris, Kyle A. Reeves, Allison M. Vissichelli

Environmental Studies Faculty Publications

Mussels (Mytilus edulis) build massive, spatially complex, biogenic structures that alter the biotic and abiotic environment and provide a variety of ecosystem services. Unlike rocky shores, where mussels can attach to the primary substrate, soft sediments are unsuitable for mussel attachment. We used a simple lattice model, field sampling, and field and laboratory experiments to examine facilitation of recruitment (i.e., preferential larval, juvenile, and adult attachment to mussel biogenic structure) and its role in the development of power-law spatial patterns observed in Maine, USA, soft-bottom mussel beds. The model demonstrated that recruitment facilitation produces power-law spatial structure similar to ...


Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson Dec 2014

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses and Project Reports

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced ...


Using Migration Monitoring Data To Assess Bird Population Status And Behavior In A Changing Environment, Evan M. Adams Dec 2014

Using Migration Monitoring Data To Assess Bird Population Status And Behavior In A Changing Environment, Evan M. Adams

Electronic Theses and Dissertations

Across the world, researchers use migration banding stations to document bird migration and study the phenomenon. In this dissertation, I focus on ways of analyzing bird migration banding data and the utility migrating birds as indicators of ecosystem health that make these monitoring efforts more useful to answering ecological questions and managing migratory species. In Chapter 1, we provide background on hierarchical modeling and an overview of our findings. In Chapter 2, we developed and validated new methods to estimate daily changes in migratory population size while controlling for changes in detectability due to environmental conditions. In Chapter 3, this ...


Scaling Ecosystem Services To Reef Development : Effects Of Oyster Density On Nitrogen Removal And Reef Community Structure, Lisa M. Kellogg, Jeffrey C. Cornwell, Michael S. Owens, Mark W. Luckenbach, Paige G. Ross, Thomas A. Leggett Nov 2014

Scaling Ecosystem Services To Reef Development : Effects Of Oyster Density On Nitrogen Removal And Reef Community Structure, Lisa M. Kellogg, Jeffrey C. Cornwell, Michael S. Owens, Mark W. Luckenbach, Paige G. Ross, Thomas A. Leggett

Reports

Eighteen native oyster experimental reefs (16-m2 each) were restored using six oyster densities (0, 10, 25, 50, 100 and 250 adult oysters m-2) with three replicates of each density at each of two sites: one subtidal site in Onancock Creek, Virginia and one intertidal site in Hillcrest Oyster Sanctuary within The Nature Conservancy’s Virginia Coast Reserve. A science-based monitoring program explored quantitative relationships between structural and functional characteristics of these restored reefs. Structural parameters examined included oyster abundance, oyster size/biomass, surface shell volume, reef topographic complexity and sediment characteristics. Functional parameters included denitrification rates and macrofaunal abundance and ...