Digital Commons Network^™

Good Press, Bad Press: A 25-Year Comparison Of Arguments And Trends In American News Coverage Of Climate Change And The Ozone Hole, David Howland

Doctoral Dissertations

This study uses an original content analysis categorical system to seek out and compare the substance of arguments in a quarter century of American news coverage about the ozone hole and climate change. Findings from an examination of more than 1,000 news articles written by The Associated Press, United Press International and The New York Times are combined with interviews with members of key stakeholder groups in both cases including scientists, politicians, industry officials, environmentalists and news reporters. The analysis illuminates the social and political processes at work---that is, those captured by the press---in the evolution of the Montreal ozone …

Assessing The Accuracy Of The Modis Lai 1-Km Product In Southeastern United States Loblolly Pine Plantations: Accounting For Measurement Variance From Ground To Satellite, John Shepherd Iiames Jr.

Doctoral Dissertations

Leaf area index (LAI), defined here as one-half of the total leaf area per unit ground surface area (Chen, 1996), has been estimated at a global scale from spectral data processed from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard two NASA EOS-AM spacecraft, Terra (launched in 1999) and Aqua (launched in 2002). The MOD15A2 LAI product is a 1 km global data product composited over an 8-day period and is derived from a three-dimensional radiative transfer model driven by an atmosphere corrected surface reflectance product (MOD09), a land cover product (MOD12) and ancillary information on surface characteristics. The United …

Gonadal Histology And Reproductive Steroidogenesis Of Anurans Exposed To Potential Endocrine Disrupting Contaminants, Emily May La Fiandra

Doctoral Dissertations

The prevalence of malformed amphibians and the association of high incidences of malformation with the presence of environmental contaminants have raised questions about the effects of environmental contaminants on the development of larval amphibians. The potential endocrine disrupting effects of pesticides suggest that the reproductive and developmental abnormalities observed in larval anurans may be due at least in part to impacts on the hypothalamic-pituitary-gonadal axis. The present studies investigate the effects of exposure to environmental contaminants including DDT and atrazine on the development, gonadal histology and reproductive steroidogenesis of larval anurans.

As previous monitoring at Great Bay National Wildlife Refuge …

Remote Detection Of Forest Structure In The White Mountains Of New Hampshire: An Integration Of Waveform Lidar And Hyperspectral Remote Sensing Data, Jeanne Elizabeth Anderson

Doctoral Dissertations

The capability of waveform lidar, used singly and through integration with high-resolution spectral data, to describe and predict various aspects of the structure of a northern temperate forest is explored. Waveform lidar imagery was acquired in 1999 and 2003 over Bartlett Experimental Forest in the White Mountains of central New Hampshire using NASA's airborne Laser Vegetation Imaging Sensor (LVIS). High-resolution spectral imagery from 1997 and 2003 was likewise acquired using NASA's Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). USDA Forest Service Northeastern Research Station (USFS NERS) 2001-2003 inventory data was used to define basal area, above-ground biomass, quadratic mean stem diameter and …

Recent Extreme Events In A Tropical Stalagmite: Multi-Proxy Records And Analysis Of Ecosystem Delta Carbon-13 Value Sensitivity To Weak Climate Forcing, Amy E Benoit Frappier

Doctoral Dissertations

Speleothems are emerging as important and detailed chronological records of environmental change. Integrating exploration of modern speleothem records of environmental variability, related forcing factors, and understanding and suggests new potential proxies. This dissertation demonstrates the potential for developing novel proxy records of past regional environmental extremes, such as tropical cyclones, explosive volcanism, and enhanced seasonal contrasts from speleothems that are sensitive to transient infiltration events through very high-resolution, multi-parameter analysis of a rapidly growing, fracture-fed tropical stalagmite. A series of sample screening steps were developed prior to stalagmite collection in the field in order to increase the likelihood of collecting …

Atmospheric Volatile Organic Compound Measurements: Distributions And Effects On Air Quality In Coastal Marine, Rural And Remote Continental Environments, Yong Zhou

Doctoral Dissertations

A detailed description of the analytical methods employed for whole air sampling and analysis of atmospheric volatile organic compounds is presented. The system described in this thesis produced high precision measurements for a large suite of nonmethane hydrocarbons, halocarbons, and alkyl nitrates, from part per billion by volume (ppbv) to part per trillion by volume (pptv) levels. The measurement precision for most gases ranged from 1-10%.

Results from two subsequent field campaigns (2002 and 2003) conducted in Yellowstone National Park (YNP) are presented. The findings indicate that 2-stroke snowmobile engine emissions furnish large quantities of air toxics to the YNP …

Ecological Patterns, Community Classification, And A Comparison Of Approaches For Predicting Biological And Habitat Reference Conditions In New Hampshire Streams, Brian R. Frappier

Doctoral Dissertations

Reference conditions play a vital role in many challenges facing both conservation and natural resources management. This dissertation sought to establish minimally-impacted reference conditions for stream biota and habitat in New Hampshire and explore alternative statistical methodologies to predict reference conditions for biological and habitat assessments. The fish, stream-dwelling salamander, macroinvertebrate and periphyton assemblages as well as the co-occurring physical habitat and riparian conditions of 76 minimally-impacted first to fourth order streams in New Hampshire were estimated using USEPA Environmental Monitoring and Assessment Program protocols over a four year period. Several statistical approaches and data standardizations for classifying multi-taxonomic assemblages …

Uptake And Growth Effects Of Polycyclic Aromatic Hydrocarbons In Wetland Plants, Alison Watts

Doctoral Dissertations

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in estuarine environments, but little is known about the distribution and fate of PAHs in wetland sediments and plants. The effect of PAHs on common salt marsh plants, and the PAH distribution within the plants, sediment, and atmosphere were evaluated to determine if PAHs were transported from the sediment into the plants, and if the PAHs affected plant growth. Four salt marsh plant species, Spartina alterniflora, Phragmites australis, Solidago sempervirens and Distichlis spicata were grown in pots of PAH contaminated sediment containing mean total PAH concentrations of 355 mg/kg (ppm). During the growing …

Tropical Forest Structure: Ground Measurements Of Coarse Necromass And Satellite Observations Of Crown Geometry, Michael W. Palace

Doctoral Dissertations

Forests are structurally diverse, but these structures derive from the same processes of disturbance and growth. Understanding forest structure can help unlock the history, function, and future of a forested ecosystem. Components of forest structure include tree size distributions, foliage distributions and variation in canopy density, and coarse woody debris (coarse necromass). Tropical rainforests are structurally the most complex of all ecosystems. In addition to having high biological diversity, Amazon forests are marked by complex vegetation dynamics and a diverse forest stand structures, which play an important role in the interactions of water and carbon between the biosphere and atmosphere. …

Characterization Of The Spatial And Temporal Variability In Pan-Arctic, Terrestrial Hydrology, Michael A. Rawlins

Doctoral Dissertations

Arctic hydrology represents an important component of the larger global climate system, and there are signs that significant water-cycle changes, involving complex feedbacks, have occurred. This dissertation explores the methods to estimate components of the arctic hydrological cycle, the numerous biases and uncertainties associated with the techniques, and suggestions for future research needs. The studies described here focus on quantitative models and methods for predicting the spatial and temporal variability in pan-Arctic hydrology.

This dissertation discusses pan-Arctic water budgets drawn from a hydrological model which is appropriate for applications across the terrestrial Arctic. Including effects from soil-water phase changes results …

Non-Reactive Gas Dynamics In The Piscataqua Estuary Inlet, Takashi Kalani Brown

Master's Theses and Capstones

For 135 days, from late autumn 2005 to the mid---spring 2006, continuous measurements of dissolved nitrogen, oxygen, and carbon dioxide in near surface seawater were recorded at the interface between the Great Bay-Piscataqua Estuary and the western Gulf of Maine. These surface measurements were made to investigate air-sea gas fluxes and identify the primary controls over gas dynamics in a macrotidal estuary entryway, the estuary inlet. Wind-parameterized air-sea flux estimations were calculated using published flux models and were evaluated to determine their appropriateness in the estuary inlet. Also, using supporting sea-state measurements from buoys (wind speed and wave height), the …

Understanding Changes In Aboveground Biomass And Height With Elevation At Hubbard Brook Experimental Forest, Mariya Schilz

Master's Theses and Capstones

A better understanding of carbon stocks and fluxes is a priority of many national and international agencies, including NASA, NACP, IPCC, and IGBP. (Asrar et al. 2001, IGBP Annual Report, 2003, IPCC Third Assessment Report: Climate Change 2001). Patterns of carbon stocks and fluxes on the land surface are important for studies of the carbon cycle, climate change, and terrestrial ecology. One source of heterogeneity is associated with elevation. In systems around the world, patterns in carbon stocks, fluxes, and the factors that underlie them have well documented relationships with elevation (Korner 1999, Schwarz et al. 2003, Waide et al. …

Effects Of Forest Clear Cutting On Spotted Salamander ( Ambystoma Maculatum) Migration, Jessica Susannah Veysey

Master's Theses and Capstones

Upland buffer zones are a proposed management tool for vernal-pool-breeding amphibians. Substantial validation of buffers, via experimental upland habitat disturbance, is lacking. Specifically, no studies have examined immediate effects of clear cutting on spotted salamander (Ambystoma maculatum ) migration. I used clear cutting to experimentally manipulate upland buffer widths at 11 vernal pools. I then radiotracked 40 adult spotted salamanders at these pools, and modeled their migration with mixed-effects regression. Mean maximum distance from the pool was 106.0 +/- 15.4 m (range = 1.6 to 427.6 m). At clear cut-treatment pools, mean percent of time in the cut was 27.2 …

Improving The Policy Making Process In Municipal Solid Waster Management: Learning From Minamata-City, Japan, Rika Ikemoto

Master's Theses and Capstones

Many countries, especially industrialized countries, are facing a crisis in municipal solid waste (MSW) problems due to its ever increasing amount and related problems such as limited dumping space, transboundary waste movement, financial pressures, and dioxin problems. In Japan, one of those industrialized countries, while national MSW policies have not appeared effective, some municipalities have established remarkable policies to reduce MSW Minamata-city, which has a unique experience of environmental pollution, known as Minamta-disease, has reduced waste with the two major MSW policies: a Recycling Program; and the Food-containers Abolition Project of the Women's Committee on Waste Reduction, based on the …

Cape Wind: Public Values And Perceptions Application Of Contingent Valuation Method, Eric Steltzer

Master's Theses and Capstones

The Cape Wind proposal to build 130 turbines in Nantucket sound has been a central figure in development of renewable energy in New England. The aim of this study was two fold. First, the contingent valuation method was used to estimate an economic value the public has on policy for the preservation of Nantucket sound, within the scopes of the project. The second goal was to identify lessons that could be learned from the Cape Wind proposal and applied to future renewable energy projects in New England.

Results revealed that the public has a positive economic value for a policy …