Engineering Commons^™

Estimation Of Solute Fluxes From Ungaged Headwater Catchments In The Catskill Park Of New York State, Chris Gianfagna

Civil and Environmental Engineering - Theses

Predictions of flow and subsequent solute fluxes from ungaged basins have important implications both for water resources management and ecosystem monitoring studies. The Catskill region of New York State is one such place that requires both water resources management and ecosystem monitoring due to its strategic location as the main water-supplying region for New York City. This study examines the differences in chemical mass flux estimates made in ungaged basins using three different chemistry aggregation methods for solute concentrations determined from monthly grab samples. The efficacy of area ratios for predicting flow at the upstream location of a nested pair …

Spatial Patterns Of Mercury In Atmospheric Deposition, Soils And Lake Biota In The Adirondack Park, New York, Xue Yu

Civil and Environmental Engineering - Dissertations

Mercury (Hg), as a trace element cycling in the environment, poses a serious health threat to both humans and wildlife due to its toxicity. Atmospheric deposition is the main source of Hg to most remote environments. The Adirondack Park in New York State of the United States receives moderate Hg deposition, and is a region characterized by relatively high concentrations of Hg in the terrestrial and especially aquatic biota. It is important to understand the mechanisms that contribute to the sensitivity of this region to Hg inputs. In my research, studies of the spatial patterns of Hg in atmospheric deposition, …

Long-Term Integrated Studies Show Complex And Surprising Effects Of Climate Change In The Northern Hardwood Forest, Peter M. Groffman, Charles T. Driscoll, Chris E. Johnson, Lindsey E. Rustad, Pamela H. Templer

Civil and Environmental Engineering

Evaluations of the local effects of global change are often confounded by the interactions of natural and anthropogenic factors that overshadow the effects of climate changes on ecosystems. Long-term watershed and natural elevation gradient studies at the Hubbard Brook Experimental Forest and in the surrounding region show surprising results demonstrating the effects of climate change on hydrologic variables (e.g., evapotranspiration, streamflow, soil moisture); the importance of changes in phenology on water, carbon, and nitrogen fluxes during critical seasonal transition periods; winter climate change effects on plant and animal community composition and ecosystem services; and the effects of anthropogenic disturbances and …

Modeling Potential Hydrochemical Responses To Climate Change And Increasing Co2 At The Hubbard Brook Experimental Forest Using A Dynamic Biogeochemical Model (Pnet-Bgc), Afshin Pourmokhtaria, Charles T. Driscoll, John L. Campbell, Katharine Hayhoe

Civil and Environmental Engineering

Dynamic hydrochemical models are useful tools for understanding and predicting the interactive effects of climate change, atmospheric CO2, and atmospheric deposition on the hydrology and water quality of forested watersheds. We used the biogeochemical model, PnET-BGC, to evaluate the effects of potential future changes in temperature, precipitation, solar radiation, and atmospheric CO2 on pools, concentrations, and fluxes of major elements at the Hubbard Brook Experimental Forest in New Hampshire, United States. Future climate projections used to run PnET-BGC were generated specifically for the Hubbard Brook Experimental Forest with a statistical technique that downscales climate output (e.g., air temperature, precipitation, solar …

Recovery Of Sensitive Watersheds In The Northeastern United States From Chronic Acidification: The Role Of Soil Chemistry, Chris E. Johnson

Civil and Environmental Engineering

No abstract provided.

Science And Society: The Role Of Long-Term Studies In Environmental Stewardship, Charles T. Driscoll, Kathleen F. Lambert, F. Stuart Chapin, David J. Nowake, Thomas A. Spies, Frederick J. Swanson, David B. Kittredge, Clarisse M. Hart

Civil and Environmental Engineering

Long-term research should play a crucial role in addressing grand challenges in environmental stewardship. We examine the efforts of five Long Term Ecological Research Network sites to enhance policy, management, and conservation decisions for forest ecosystems. In these case studies, we explore the approaches used to inform policy on atmospheric deposition, public land management, land conservation, and urban forestry, including decisionmaker engagement and integration of local knowledge, application of models to analyze the potential consequences of policy and management decisions, and adaptive management to generate new knowledge and incorporate it into decisionmaking. Efforts to enhance the role of long-term research …

Watershed-Level Responses To Calcium Silicate Treatment In A Northern Hardwood Forest, Youngil Cho, Charles T. Driscoll, Chris E. Johnson, Joel D. Blum, Timothy J. Fahey

Civil and Environmental Engineering

Watershed 1 (W1) at the Hubbard Brook Experimental Forest in New Hampshire, with chronically low pH and acid neutralizing capacity (ANC) in surface water, was experimentally treated with calcium silicate (CaSiO₃; wollastonite) in October 1999 to assess the role of calcium (Ca) supply in the structure and function of base-poor forest ecosystems. Wollastonite addition significantly increased the concentrations and fluxes of Ca, dissolved silica (Si), and ANC and decreased the concentrations and fluxes of inorganic monomeric Al (Al_i) and hydrogen ion (H⁺) in both soil solution and stream water in all sub-watersheds of W1. …

Marine Mercury Fate: From Sources To Seafood Consumers, Celia Y. Chen, Charles T. Driscoll, Kathy Lambert, Robert P. Mason, Laurie Rardin

Civil and Environmental Engineering

No abstract provided.

A Synthesis Of Rates And Controls On Elemental Mercury Evasion In The Great Lakes Basin, Joseph S. Denkenberger, Charles T. Driscoll, Brian A. Branfireun, Chris S. Eckley, Mark Cohen, Pranesh Selvendiran

Civil and Environmental Engineering

Rates of surface-air elemental mercury (Hgo) fluxes in the literature were synthesized for the Great Lakes Basin (GLB). For the majority of surfaces, fluxes were net positive (evasion). Digital land-cover data were combined with representative evasion rates and used to estimate annual Hgo evasion for the GLB (7.7 Mg/yr). This value is less than our estimate of total Hg deposition to the area (15.9 Mg/yr), suggesting the GLB is a net sink for atmospheric Hg. The greatest contributors to annual evasion for the basin are agricultural (~55%) and forest (~25%) land cover types, and the open water of the Great …

Nutrient Supply And Mercury Dynamics In Marine Ecosystems: A Conceptual Model, Charles T. Driscoll, Celia Y. Chen, Chad R. Hammerschmidt, Robert P. Mason, Cynthia C. Gilmour

Civil and Environmental Engineering

There is increasing interest and concern over the impacts of mercury (Hg) inputs to marine 32 ecosystems. One of the challenges in assessing these effects is that the cycling and trophic 33 transfer of Hg are strongly linked to other contaminants and disturbances. In addition to Hg, a 34 major problem facing coastal waters is the impacts of elevated nutrient, particularly nitrogen 35 (N), inputs. Increases in nutrient loading alter coastal ecosystems in ways that should change 36 the transport, transformations and fate of Hg, including increases in fixation of organic carbon 37 and deposition to sediments, decreases in the …

Nutrient Supply And Mercury Dynamics In Marine Ecosystems: A Conceptual Model, Charles T. Driscoll, Celia Y. Chen, Chad R. Hammerschmidt, Robert P. Mason, Cynthia C. Gilmour, Elsie M. Sunderland, Ben K. Greenfield, Kate L. Buckman, Carl H. Lamborg

Civil and Environmental Engineering

There is increasing interest and concern over the impacts of mercury (Hg) inputs to marine ecosystems. One of the challenges in assessing these effects is that the cycling and trophic transfer of Hg are strongly linked to other contaminants and disturbances. In addition to Hg, a major problem facing coastal waters is the impacts of elevated nutrient, particularly nitrogen (N), inputs. Increases in nutrient loading alter coastal ecosystems in ways that should change the transport, transformations and fate of Hg, including increases in fixation of organic carbon and deposition to sediments, decreases in the redox status of sediments and changes …

Shift Towards P Limitation With N Deposition?, K. F. Crowley, B. E. Mcneil, G. M. Lovett, C. D. Canham, C. T. Driscoll

Civil and Environmental Engineering

Atmospheric nitrogen (N) deposition is altering biogeochemical cycling in forests and interconnected lakes of the northeastern US, and may shift nutrient limitation from N toward other essential elements, such as phosphorus (P). Whether this shift is occurring relative to N deposition gradients across the northeastern US has not been investigated. We used datasets for the northeastern US and the Adirondack sub-region to evaluate whether P limitation is increasing where N deposition is high at two geographic scales, based on N:P mass ratios. Using a model- selection approach, we determined that foliar N for dominant tree species and lake dissolved inorganic …

Combined Heat, Air Moisture And Pollutant Simulations (Champs) For Buildings, Jianshun Zhang, Menghao Qin

Mechanical and Aerospace Engineering - All Scholarship

No abstract provided.

Effects Of Calcium Addition On Structure And Bioavailability Of Soil Organic Matter, Ankit Balaria

Civil and Environmental Engineering - Dissertations

The northeastern USA has a long history of acid rain, which has impacted soil fertility and raised concerns about the sustainability of the forests in the region. To facilitate recovery of these forests, calcium addition, in the form of wollastonite, was evaluated as a remedial tool at Hubbard Brook Experimental Forests in New Hampshire, USA. In order to study the effects of these amendments on soil organic matter and soil microbes, I characterized the structural chemistry of soil organic matter (SOM) and its hot-water extractable organic matter (HWEOM) fraction for Hubbard Brook soils and studied the changes in the structure …

Soil Chemistry And The Recovery Of Sensitive Watersheds From Chronic Acidification, Chris E. Johnson

Civil and Environmental Engineering

No abstract provided.

Integrating Science And Policy: A Case Study Of The Hubbard Brook Research Foundation Science Links Program, Charles T. Driscoll, Kathy Fallon Lambert, Kathleen C. Weathers

Civil and Environmental Engineering

Scientists, related professionals, and the public have for decades called for greater interaction among scientists, policymakers, and the media to address contemporary environmental challenges. Practical examples of effective “real-world” programs designed to catalyze interactions and provide relevant science are few. Existing successful models can be used, however, to develop and expand the work of integrating, synthesizing, and communicating ecosystem science for environmental policy and natural-resource management. We provide an overview of the structure and strategies used in the Hubbard Brook Research Foundation Science Links program, now in its thirteenth year as a successful boundary-spanning organization. We detail project activities and …

Empirical Critical Loads Of Atmospheric Nitrogen Deposition For Nutrient Enrichment And Acidification Of Sensitive Us Lakes, Jill S. Baron, Charles T. Driscoll, John L. Stoddard, Eric E. Richer

Civil and Environmental Engineering

No abstract provided.

Dynamics Of Oxidized And Reduced Iron In A Northern Hardwood Forest, Colin B. Fuss, Charles T. Driscoll, Chris E. Johnson, Robert J. Petras, Timothy J. Fahey

Civil and Environmental Engineering

Iron (Fe) is ubiquitous in forest ecosystems and its cycle is thought to influence the development of soil, particularly Spodosols (podsolization), and the biogeochemistry of macronutrients such as carbon (C), nitrogen (N), and phosphorus (P), as well as many trace metals. The cycle of Fe in northern hardwood forests remains poorly understood. To address some of these uncertainties, we constructed a biogeochemical budget of Fe for a small catchment at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA. Horizonal, temporal, and elevational patterns of concentrations and fluxes of oxidized and reduced Fe species were assessed …

Using Equal‐Area Quadratic Splines To Compute Depth‐ Weighted Averages Of Soil Chemical Parameters, Chris E. Johnson, Jeremy Tamargo

Civil and Environmental Engineering

No abstract provided.

Accidental Releases Of Hazardous Materials And Relevance To Terrorist Threats At Industrial Facilities, Laura J. Steinberg, Nicholas Santella

Civil and Environmental Engineering

Hazardous material releases, some with serious consequences, are a common occurrence in the U.S. Of late, the hazards posed by releases caused by terrorist attacks or natural disasters have been of particular concern. Although terrorism directed at hazardous material handling industries within the U.S. has not yet resulted in a significant incident, there is much recent experience with serious accidental releases resulting from natural disasters. Case studies are developed from a number of recent natural disasters and severe weather events that resulted in large releases of hazardous materials. These case studies are used to illustrate parallels between the risks posed …

Spatial And Temporal Patterns Of Mercury Accumulation In Lacustrine Sediments Across The Laurentian Great Lakes Region, Paul E. Drevnick, Daniel R. Engstrom, Charles T. Driscoll, Edward B. Swain, Steven J. Balogh

Civil and Environmental Engineering

Data from 104 sediment cores from the Great Lakes and “inland lakes” in the region were compiled to assess historical and recent changes in mercury (Hg) deposition. The lower Great Lakes showed sharp increases in Hg loading c. 1850-1950 from point-source water dischargers, with marked decreases during the past half century associated with effluent controls and decreases in the industrial use of Hg. In contrast, Lake Superior and inland lakes exhibited a pattern of Hg loading consistent with an atmospheric source - gradual increases followed by recent (post-1980) decreases. Variation in sedimentary Hg flux among inland lakes was primarily attributed …

Effects Of Nitrogen Deposition And Empirical Nitrogen Critical Loads For Ecoregions Of The United States, Linda H. Pardo, Mike E. Fenn, Christine L. Goodale, Linda. H. Geiser, Charles T. Driscoll, Edith B. Allen, Jill S. Baron, Roland Bobbink, Williams D. Bowman, Christopher M. Clark, Bridget Emmett, Frank S. Gilliam, Tara L. Greaver, Sharon J. Hall, Erik A. Lilleskov, Lingli Liu, Jason A. Lynch, Knute J. Nadelhoffer, Steven S. Perakis, Molly J. Robin-Abbott, John L. Stoddard, Kathleen C. Weathers, Robin L. Dennis

Civil and Environmental Engineering

Human activity in the last century has led to a significant increase in nitrogen (N) emissions and atmospheric deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the deposition of pollution that would be harmful to ecosystems is the determination of critical loads. A critical load is defined as the input of a pollutant below which no detrimental ecological effects occur over the long-term according to present knowledge.

The objectives of this project were to synthesize …

Chemical Changes In Soil And Soil Solution After Calcium Silicate Addition To A Northern Hardwood Forest, Youngil Cho, Charles T. Driscoll, Chris E. Johnson, Thomas G. Siccama

Civil and Environmental Engineering

Liming has been used to mitigate effects of acidic deposition in forest ecosystems. This study was designed to examine the effects of calcium (Ca) supply on the spatial patterns and the relations between soil and soil solution chemistry in a base-poor forest watershed. Watershed 1 at the Hubbard Brook Experimental Forest in New Hampshire, USA was experimentally treated with wollastonite (CaSiO₃) in October, 1999. Exchangeable Ca (Ex-Ca), soil pH_s (in 0.01 M CaCl₂), effective cation exchange capacity (CEC_e), and effective base saturation (BS_e) increased, while exchangeable acidity (Ex-Acid) decreased …

Long-Term Changes In Aluminum Fractions Of Drainage Waters In Two Forest Catchments With Contrasting Lithology, Pavel Krám, Jakub Hruška, Charles T. Driscoll, Chris E. Johnson, Filip Oulehle

Civil and Environmental Engineering

Aluminum (Al) chemistry was studied in soils and waters of two catchments covered by spruce (Picea abies) monocultures in the Czech Republic that represent geochemical end-members of terrestrial and aquatic sensitivity to acidic deposition. The acid-sensitive Lysina catchment, underlain by granite, was compared to the acid-resistant Pluhův Bor catchment on serpentine. Organically-bound Al was the largest pool of reactive soil Al at both sites. Very high median total Al (Alt) concentrations (40 μmol L⁻¹) and inorganic monomeric Al (Ali) concentrations (27 μmol L⁻¹) were observed in acidic (pH 4.0) stream water at Lysina in …

Long-Term Trends From Ecosystem Research At The Hubbard Brook Experimental Forest, John L. Campbell, Charles T. Driscoll, Christopher Eagar, Gene E. Likens, Thomas G. Siccama, Chris E. Johnson, Timothy J. Fahey, Steven P. Hamburg, Richard T. Holmes, Amey S. Bailey, Donald C. Buso

Civil and Environmental Engineering

The Hubbard Brook Experimental Forest was established by the U.S. Forest Service in 1955 as a major center for hydrologic research in the Northeast. The Hubbard Brook Ecosystem Study originated 8 years later with the idea of using the small watershed approach to study element flux and cycling and the response of forest ecosystems to disturbance. Since that time, the research program at Hubbard Brook has expanded to include various physical, chemical and biological measurements collected by researchers from a number of cooperating institutions. Collaborative, long-term data are the keystone of the Hubbard Brook Ecosystem Study and have provided invaluable …

Mercury Contamination In Forest And Freshwater Ecosystems In The Northeastern United States, Charles T. Driscoll, Young-Ji Han, Celia Y. Chen, David C. Evers, Kathleen Fallon Lambert

Civil and Environmental Engineering

Eastern North America receives elevated atmospheric mercury deposition from a combination of local, regional, and global sources. Anthropogenic emissions originate largely from electric utilities, incinerators, and industrial processes. The mercury species in these emissions have variable atmospheric residence times, which influence their atmospheric transport and deposition patterns. Forested regions with a prevalence of wetlands and of unproductive surface waters promote high concentrations of mercury in freshwater biota and thus are particularly sensitive to mercury deposition. Through fish consumption, humans and wildlife are exposed to methylmercury, which markedly bioaccumulates up the freshwater food chain. Average mercury concentrations in yellow perch fillets …