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Monitoring Soil Response To Decreasing Acidic Deposition In A Western Adirondack Tributary Over A 16 Year Period, Michael Robert Antidormi Jan 2015

Monitoring Soil Response To Decreasing Acidic Deposition In A Western Adirondack Tributary Over A 16 Year Period, Michael Robert Antidormi

Legacy Theses & Dissertations (2009 - 2024)

Abstract


Using Storm-Watersheds And A Multi-Criteria Decision Model For Biodiversity Conservation In An Urban Environment, Christina M. Chiappetta Jan 2015

Using Storm-Watersheds And A Multi-Criteria Decision Model For Biodiversity Conservation In An Urban Environment, Christina M. Chiappetta

Legacy Theses & Dissertations (2009 - 2024)

Many planning and land use decisions in New York State are controlled at the local (town or municipal) level, not an optimal scale for planning and implementing resource conservation management. Watershed boundaries provide a more ecologically meaningful scale for conservation, because they capture a full range of natural ecosystem processes that span political boundaries. However, defining an urban watershed is complicated by stormwater infrastructure, so standard topographic watershed boundaries may be inadequate for urban resource conservation even when applied at the watershed scale. Storm-watersheds distort both municipal and watershed boundaries, because the flows are redirected in ways that are often …


Wetchimp-Wsl: Intercomparison Of Wetland Methane Emissions Models Over West Siberia, T. J. Bohn, J. R. Melton, A. Ito, T. Kleinen, R. Spahni, B. D. Stocker, B. Zhang, X. Zhu, R. Schroeder, M. V. Glagolev, S. Maksyutov, V. Brovkin, G. Chen, S. N. Denisov, A. V. Eliseev, A. Gallego-Sala, K. C. Mcdonald, M. A. Rawlins, W. J. Riley, Z. M. Subin, H. Tian, Q. Zhuang, J. O. Kaplan Jan 2015

Wetchimp-Wsl: Intercomparison Of Wetland Methane Emissions Models Over West Siberia, T. J. Bohn, J. R. Melton, A. Ito, T. Kleinen, R. Spahni, B. D. Stocker, B. Zhang, X. Zhu, R. Schroeder, M. V. Glagolev, S. Maksyutov, V. Brovkin, G. Chen, S. N. Denisov, A. V. Eliseev, A. Gallego-Sala, K. C. Mcdonald, M. A. Rawlins, W. J. Riley, Z. M. Subin, H. Tian, Q. Zhuang, J. O. Kaplan

Publications and Research

Wetlands are the world’s largest natural source of methane, a powerful greenhouse gas. The strong sensitivity of methane emissions to environmental factors such as soil temperature and moisture has led to concerns about potential positive feedbacks to climate change. This risk is particularly relevant at high latitudes, which have experienced pronounced warming and where thawing permafrost could potentially liberate large amounts of labile carbon over the next 100 years. However, global models disagree as to the magnitude and spatial distribution of emissions, due to uncertainties in wetland area and emissions per unit area and a scarcity of in situ observations. …


Regional Scale Cropland Carbon Budgets: Evaluating A Geospatial Agricultural Modeling System Using Inventory Data, Xuesong Zhang, Roberto C. Izaurralde, David H. Manowitz, Ritvik Sahajpal, Tristram O. West, Allison M. Thomson, Min Xu, Kaiguang Zhao, Stephen D. Leduc, Jimmy R. Williams Jan 2015

Regional Scale Cropland Carbon Budgets: Evaluating A Geospatial Agricultural Modeling System Using Inventory Data, Xuesong Zhang, Roberto C. Izaurralde, David H. Manowitz, Ritvik Sahajpal, Tristram O. West, Allison M. Thomson, Min Xu, Kaiguang Zhao, Stephen D. Leduc, Jimmy R. Williams

United States Environmental Protection Agency: Publications

Accurate quantification and clear understanding of regional scale cropland carbon (C) cycling is critical for designing effective policies and management practices that can contribute toward stabilizing atmospheric CO2 concentrations. However, extrapolating site-scale observations to regional scales represents a major challenge confronting the agricultural modeling community. This study introduces a novel geospatial agricultural modeling system (GAMS) exploring the integration of the mechanistic Environmental Policy Integrated Climate model, spatially-resolved data, surveyed management data, and supercomputing functions for cropland C budgets estimates. This modeling system creates spatiallyexplicit modeling units at a spatial resolution consistent with remotely-sensed crop identification and assigns cropping systems …


Analyses Of Potential Ravine And Bluff Stabilization Sites Within The Blue Earth And Le Sueur River Basins, Anna My-Tien T. Tran Jan 2015

Analyses Of Potential Ravine And Bluff Stabilization Sites Within The Blue Earth And Le Sueur River Basins, Anna My-Tien T. Tran

All Graduate Theses, Dissertations, and Other Capstone Projects

The United States Environmental Protection Agency (USEPA) has listed much of the Upper Mississippi River (UMR) basin as impaired waters due to excessive turbidity, sedimentation, and nutrient loading. Of particular importance are the associated environmental problems (e.g. eutrophication, habitat and wetland loss, loss of biodiversity, and changes in water quality) that have developed within Lake Pepin, a popular recreational riverine lake of the UMR. Three major drainages contribute to these issues and empty in to the UMR near Lake Pepin - the Minnesota River Basin (MRB), St. Croix River, and UMR. The MRB makes up approximately one-third of the drainage …


Innovation Or Inundation: The Political Economy Of Sea Level Rise In The San Francisco Bay Area, Nicole Quilliam Jan 2015

Innovation Or Inundation: The Political Economy Of Sea Level Rise In The San Francisco Bay Area, Nicole Quilliam

Pomona Senior Theses

Sea levels are rising around the world due to climate change and the rise in greenhouse gas emissions causing an environmental climate crisis. This thesis paper analyzes how sea level rise is affecting the San Francisco Bay Area. It walks through the geographical factors contribute to more severe impacts of sea level rise, potential adaptation strategies, and discusses the economic impacts and political challenges of protecting communities from sea level rise.


University Of North Florida Environmental Center Annual Report 2015, Caitlin Kengle, James W. Taylor Jan 2015

University Of North Florida Environmental Center Annual Report 2015, Caitlin Kengle, James W. Taylor

Annual Reports

2015 Annual Report of the Environmental Center at the University of North Florida


Investigating Diurnal And Seasonal Climatic Response To Land Use And Land Cover Change Over Monsoon Asia With The Community Earth System Model, Rezaul Mahmood Jan 2015

Investigating Diurnal And Seasonal Climatic Response To Land Use And Land Cover Change Over Monsoon Asia With The Community Earth System Model, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.


Increasing Access To Natural Areas: Connecting Physical And Social Dimensions, Bradford S. Gentry, Jazmine Da Costa, Katie Christiansen Holsinger, W. Colby Tucker, Matthew R. Viens Jan 2015

Increasing Access To Natural Areas: Connecting Physical And Social Dimensions, Bradford S. Gentry, Jazmine Da Costa, Katie Christiansen Holsinger, W. Colby Tucker, Matthew R. Viens

Yale School of the Environment Publications Series

Report of the 2015 Berkley Workshop

Held at the Asticou Inn, Northeast Harbor, Maine - July 2015


San Diego’S Options For Alternate Sources Of Water: A Comparative Analysis Of Water Recycling And Desalination As Alternative Methods To Importing Water, Alana O. Pokorny Jan 2015

San Diego’S Options For Alternate Sources Of Water: A Comparative Analysis Of Water Recycling And Desalination As Alternative Methods To Importing Water, Alana O. Pokorny

Scripps Senior Theses

This paper describes the processes, methods, backgrounds, and economic challenges, of Desalination and Water Recycling and provide current examples of both. To create a baseline with which to compare the two methods, I will also delve into the history of California water policy. This complicated past is the reason water importation into Southern California remains the main method of obtaining water. Yet, as the current drought continues and technology advances, the need for imported water will become obsolete as the methods for recycling and desalinating water become less expensive, more convenient and more equitable. In the conclusion, all the methods …


Using Particle Size Analysis To Separate The Deposition Of A Bonebed And Artifact At The Wenas Creek Mammoth Site, Genevieve Brown Jan 2015

Using Particle Size Analysis To Separate The Deposition Of A Bonebed And Artifact At The Wenas Creek Mammoth Site, Genevieve Brown

All Master's Theses

The 2005 discovery of a 17,000 year old mammoth bonebed in close proximity to a possible artifact at the Wenas Creek Mammoth Site (WCMS) brought with it the question of whether the bones and artifact were actually deposited together. If the two are associated, the WCMS would qualify as a Pre-Clovis site, a title given to just a handful of proven archaeological sites in North America, though claimed for numerous more. A close interval particle size analysis was performed on 2 column samples from the WCMS with the intention of identifying microstratification that would separate the bonebed from the artifact. …


Mesoamerican Sacred Geography And Archeological Landscapes: A Case Study In The Volcanic Highlands Of Michoacan, Mexico, Jarod Scott Drozdowski Jan 2015

Mesoamerican Sacred Geography And Archeological Landscapes: A Case Study In The Volcanic Highlands Of Michoacan, Mexico, Jarod Scott Drozdowski

All Master's Theses

US and Mexican teams have investigated the La Alberca Structure Complex with the community of Parangaricutiro. Their forest reserve, located near San Juan Nuevo in Michoacan, Mexico, contains several volcanic cones, including the famous Paricutin cinder cone. Sixteen earthen-rock structures have been mapped using aerial photography, GPS, GIS, and total station surveys. The structures range from 300 to 2,400 cubic meters in volume. The larger mound-like structures are traditionally called yacatas. Early radiocarbon dates for two of the three central structures (ca. 5200-2000 BCE) bracket dates for the Late Archaic burial in the La Alberca caldera. Arrangements of the larger …


Interpretation Of Shell [Delta]180 And [Delta]13c From Two Hells Canyon Study Sites: A Methods Approach To Analysis, Nathaniel Jacob Morse Jan 2015

Interpretation Of Shell [Delta]180 And [Delta]13c From Two Hells Canyon Study Sites: A Methods Approach To Analysis, Nathaniel Jacob Morse

All Master's Theses

I analyze stable oxygen isotope ([delta]180) and stable carbon isotope ([delta]13C) data from shell at two study sites in the Hells Canyon in Oregon and Idaho. Mussel shell isotope data from two species, Margaritifera falcata and Gonidea angulata, are compared with a terrestrial snail species Oreohelix strigosa from the Tryon Creek site (35WA288) and the Bernard Creek Rockshelter (1 0IH483). There were five methodological hypotheses to test with these data. Three tests yielded no significant correlation in isotope values: M falcata vs. G. angulata, mussels vs. snails, and winter vs. summer increments of snails. A fourth test showed …


Participacion Regional En Las Iniciativas Para Reducir Emisiones De Deforestación Y Degradación Forestal En Ucayali, Peru, Megan Wing, Hasia White, Christian Graven, Mary Finley-Brook Jan 2015

Participacion Regional En Las Iniciativas Para Reducir Emisiones De Deforestación Y Degradación Forestal En Ucayali, Peru, Megan Wing, Hasia White, Christian Graven, Mary Finley-Brook

Geography and the Environment Faculty Publications

Esta investigación analiza la participación regional de las iniciativas de Reducción de Emisiones de Deforestación y Degradación Forestal (REDD) en Ucayali, Perú. Utilizamos el enfoque de escala para entender los roles de las agencias gubernamentales, las organizaciones no gubernamentales (ONG), las universidades, el sector privado, y las federaciones indígenas de la región. Nuestra metodología combina la revisión de literatura internacional con entrevistas, encuestas, y observaciones en Pucallpa y Lima efectuadas durante junio y julio del 2013 y 2014. Los resultados sugieren que: (1) existen varias tensiones dentro de los procesos de planificación de REDD en el Perú; y (2) la …


Elk And Deer Hunters In Washington State: Affiliations And Ethical Behavior, Isa O. Harrison Jan 2015

Elk And Deer Hunters In Washington State: Affiliations And Ethical Behavior, Isa O. Harrison

All Master's Theses

Elk and deer are particularly challenging natural resources to manage due to their mobility and the impacts of other species and humans both direct and indirect. A man-made lack of natural predators has created a need for hunting in order to control the population expansions of herds. Such efforts face two major problems: mobility makes herds difficult to accurately quantify and hunting laws are challenging to enforce. Policies regarding the annual take and type of hunting have been based on the assumption that the primary factor motivating hunters is harvesting more animals. However, this study has found that the primary …


Influence Of Saltwater Intrusion, Climate, And Development On The Ground Water Supply Of San Juan Island, Scott Joel Adolphson Jan 2015

Influence Of Saltwater Intrusion, Climate, And Development On The Ground Water Supply Of San Juan Island, Scott Joel Adolphson

All Master's Theses

Freshwater availability is a serious resource concern, due to the needs of its increasing population. This issue is especially critical in coastal regions, both due to supplying the growing number of people migrating to these areas and the higher potential for saltwater intrusion into groundwater supplies as water demands increase. This study assessed the degree of saltwater intrusion on San Juan Island, Washington, including its extent, contributing factors and the implication for the water resource availability. Results indicate that saltwater intrusion levels have not increased significantly in the study area, yet the size of the area threatened has increased. Saltwater …


A Study Of Resiliency In New Orleans Neighborhoods Ten Years After Hurricane Katrina, Paul Ramnauth Algu Jan 2015

A Study Of Resiliency In New Orleans Neighborhoods Ten Years After Hurricane Katrina, Paul Ramnauth Algu

LSU Master's Theses

Hurricane Katrina made landfall on August 29, 2005, flooding over eighty percent of the Greater New Orleans area and causing a mass exodus of the local population. Statistical analysis was used to quantify recovery at a neighborhood level and answer the following questions: What is the recovery rate of New Orleans neighborhoods ten years after Hurricane Katrina? What factors account for variation in recovery rates among neighborhoods? Six neighborhoods in Orleans Parish were selected for further study based on their unique geographical and recovery metrics. Recovery rates among the seventy-two neighborhoods were based on a comparison of United States Postal …


Tornado Fatalities: An In-Depth Look At Physical And Societal Influences, Heather Joann Key Jan 2015

Tornado Fatalities: An In-Depth Look At Physical And Societal Influences, Heather Joann Key

USF Tampa Graduate Theses and Dissertations

The purpose of this study is to model and determine significant predictors of tornado death index values, and to investigate these significant predictors and what makes people vulnerable to tornado fatalities through expert interviews. This study also provides an understanding of the study participant’s perceptions of their county’s vulnerability to tornado fatality and demonstrates a true integration of methods and fields by studying geographic, meteorological, and sociological phenomena by use of quantitative and qualitative methods. The study consists of two parts: 1) A quantitative exploration of variables hypothesized to predict Tornado Death Index (TDI) values, 2) A qualitative investigation to …


A Composite Spatial Model Incorporating Groundwater Vulnerability And Environmental Disturbance To Guide Land Management, Johanna L. Kovarik Jan 2015

A Composite Spatial Model Incorporating Groundwater Vulnerability And Environmental Disturbance To Guide Land Management, Johanna L. Kovarik

USF Tampa Graduate Theses and Dissertations

Research has long recognized and studied the dynamics of groundwater processes. More recently, groundwater dependent ecosystems (GDEs) are being recognized for their diversity and vulnerability to anthropogenic impact. Groundwater in karst landscapes presents a distinctive situation where flow through the subsurface often moves rapidly on the scale of days and weeks as opposed to years or millennia in other systems. This distinctive situation of karst systems and their vulnerability to human impacts necessitate an integrated and multifaceted approach for the management of these important resources. However, development of such an approach is complicated by the difficulty of obtaining detailed data …


An Ornithological Investigation Of The Relationships Among Species Assemblages In Diverse Landscapes In Portland, Oregon, Trevor Attenberg Jan 2015

An Ornithological Investigation Of The Relationships Among Species Assemblages In Diverse Landscapes In Portland, Oregon, Trevor Attenberg

Environmental Science and Management Professional Master's Project Reports

This study involves geographic variables of the urban landscape and how they affect bird species assemblage. I utilized bird point count data from observation sites in the Portland, OR metropolitan region provided by Portland Environmental Services. Species data and its relationship with environmental variables were evaluated using Bray-Curtis Dissimilarity measurements together with Non-metric Multidimensional scaling (NMDS) to provide a clear image of the spatial relationships between sites. Land classification, water and canopy in 500 m buffers were quantified in order to describe important geographic variability among collection areas of bird data. Patterns indicating spatial trends in the urban landscape emerged. …


An Analysis Of Risk Perceptions And Attitudes Towards Climate Change Among Residents Of Southeastern Louisiana, Heather Marie Brown Jan 2015

An Analysis Of Risk Perceptions And Attitudes Towards Climate Change Among Residents Of Southeastern Louisiana, Heather Marie Brown

LSU Master's Theses

Climate change is an important issue of concern, as its environmental impacts are already beginning to manifest in various means, such as through sea level rise and increased frequencies of storms. Areas of high vulnerability to the effects of climate change, such as southeastern Louisiana, are prime locations to initiate research in determining what factors influence individual’s risk perceptions towards climate change. This study aims is to identify key factors, specifically in the areas of socioeconomic, demographic, exposure, and attitudinal attributes, which affect climate change risk perceptions. The study area is that of the zip codes around Lake Pontchartrain in …


Genetic Differentiation And Phylogeography Of Partially Sympatric Species Complex Rhizophora Mucronata Lam. And R. Stylosa Griff. Using Ssr Markers, Severino G. Salmo Iii, Alison K.S Wee, Koji Takayama, Jasher L. Chua, Takeshi Asakawa, Sankararamasubramanian H. Meenakshisundaram, Onrizal Onrizal, Bayu Adjie, Erwin Riyanto Ardli, Sarawood Saengkaw, Norhaslinda Binti Malekal, Nguyen Xuan Tung, Orlex Baylen Yllano, Mohd Nazre Saleh, Khin Khin Soe, Yoichi Tateichi, Yasuyuki Watano, Shigeyuki Baba, Edward L. Webb, Tadashi Kajita Jan 2015

Genetic Differentiation And Phylogeography Of Partially Sympatric Species Complex Rhizophora Mucronata Lam. And R. Stylosa Griff. Using Ssr Markers, Severino G. Salmo Iii, Alison K.S Wee, Koji Takayama, Jasher L. Chua, Takeshi Asakawa, Sankararamasubramanian H. Meenakshisundaram, Onrizal Onrizal, Bayu Adjie, Erwin Riyanto Ardli, Sarawood Saengkaw, Norhaslinda Binti Malekal, Nguyen Xuan Tung, Orlex Baylen Yllano, Mohd Nazre Saleh, Khin Khin Soe, Yoichi Tateichi, Yasuyuki Watano, Shigeyuki Baba, Edward L. Webb, Tadashi Kajita

Environmental Science Faculty Publications

Background

Mangrove forests are ecologically important but globally threatened intertidal plant communities. Effective mangrove conservation requires the determination of species identity, management units, and genetic structure. Here, we investigate the genetic distinctiveness and genetic structure of an iconic but yet taxonomically confusing species complex Rhizophora mucronata and R. stylosa across their distributional range, by employing a suite of 20 informative nuclear SSR markers.

Results

Our results demonstrated the general genetic distinctiveness of R. mucronata and R. stylosa, and potential hybridization or introgression between them. We investigated the population genetics of each species without the putative hybrids, and found strong …


Examining The Impacts Of Valley Fills In Stream Ecosystems On Amphibian And Aquatic Insect Communities In Southeastern Kentucky, John Clayton Bourne Jan 2015

Examining The Impacts Of Valley Fills In Stream Ecosystems On Amphibian And Aquatic Insect Communities In Southeastern Kentucky, John Clayton Bourne

Online Theses and Dissertations

Chapter 1. Abstract: Biodiversity is not evenly distributed, and understanding factors that determine spatial patterns of species diversity remains a key question in ecology. Because of their relatively high abundance and complex life cycles, stream salamanders and aquatic insects are important trophic links and serve a critical role in transferring energy. Despite this importance little research has examined their community structure simultaneously in aquatic ecosystems. The primary objective of this research was to determine the structure of these communities across natural areas of southeastern Kentucky and understand what factors impact their abundances and distributions. To address this, we sampled eight …


A Comparison Of Management Strategies For The Federally Endangered Running Buffalo Clover (Trifolium Stoloniferum) On The Blue Grass Army Depot, Ky, Alexi David Dart-Padover Jan 2015

A Comparison Of Management Strategies For The Federally Endangered Running Buffalo Clover (Trifolium Stoloniferum) On The Blue Grass Army Depot, Ky, Alexi David Dart-Padover

Online Theses and Dissertations

Running buffalo clover (Trifolium stoloniferum) is a federally endangered plant that appears to depend on habitat disturbance, although proposed management strategies such as cattle grazing, mowing, and herbicide application have never been compared in a controlled study. We evaluate the efficacy of these techniques on the Blue Grass Army Depot (BGAD) in Madison County, KY, where one of T. stoloniferum’s largest populations occurs. Fifty-nine patches of T. stoloniferum on the BGAD were treated annually between 2012 and 2014 with combinations of mowing and grass-specific herbicide. Patches of T. stoloniferum also were exposed to one of three types of cattle exposure …


May You Walk In Beauty: The Decline Of Navajo Land And Culture, Jocelyn Catterson Jan 2015

May You Walk In Beauty: The Decline Of Navajo Land And Culture, Jocelyn Catterson

Undergraduate Theses, Professional Papers, and Capstone Artifacts

The Navajo homeland, Dinetah, is bordered by four mountains that are sacred to the Navajo people: two in Colorado, one in New Mexico, and one in Arizona. Historically, Navajo medicine men have traveled to these mountains to renew prayers and collect medicinal herbs. Today, the mountains, which exist outside of the reservation boundaries, are used for resource extraction and various recreational pursuits. While many Navajo are fighting for the protection of these sacred lands and their traditional culture, others are disinterested. Traditional practices and beliefs are slowly disappearing within the Navajo Nation. The land-use issues associated with these sacred mountains …


Integrating Geoscience Into Undergraduate Education About Environment, Society, And Sustainability Using Place-Based Learning: Three Examples, David Gosselin, Steven Burian, Tim Lutz, Julie Maxson Jan 2015

Integrating Geoscience Into Undergraduate Education About Environment, Society, And Sustainability Using Place-Based Learning: Three Examples, David Gosselin, Steven Burian, Tim Lutz, Julie Maxson

Department of Earth and Atmospheric Sciences: Faculty Publications

From water to energy, and from climate change to natural hazards, the geosciences (marine, Earth, and atmospheric science) have an important role to play in addressing a wide range of societal issues, with particular relevance to how humans can live sustainably on Earth. Although arguably important to developing solutions for many societal issues, more often than not, students have limited exposure to the geosciences in high school or college. To address this geoscience literacy problem, the Interdisciplinary Teaching of Geoscience for a Sustainable Future (InTeGrate) Talent Expansion Center has engaged members of the geoscience community and their colleagues in allied …


World-Wide Body Size Patterns In Freshwater Fish By Geography, Size Class, Trophic Level, And Taxonomy, Shishir Adhikari Jan 2015

World-Wide Body Size Patterns In Freshwater Fish By Geography, Size Class, Trophic Level, And Taxonomy, Shishir Adhikari

Browse all Theses and Dissertations

The unifying themes of my thesis are patterns in world-wide freshwater fish body sizes and their underlying mechanisms. First, I explored Bergmann's rule in unprecedented detail, which states that body size is negatively correlated to temperature. Categorizing species by body size into quantiles and by trophic levels, I regressed the classes against latitude, temperature, seasonality, minimum temperature and habitable space. I found that Bergmann's rule applies to freshwater fish in general but the strength varies by size class and trophic levels. I concluded that Bergmann's rule in fish is driven by the exclusion of small fish from cold climate due …


Evaluating And Prioritizing Stream Restoration In Mined Appalachian Watersheds., Eric Mitchell Miller Jan 2015

Evaluating And Prioritizing Stream Restoration In Mined Appalachian Watersheds., Eric Mitchell Miller

Graduate Theses, Dissertations, and Problem Reports (ETD)

The state of West Virginia requires stream mitigation to offset anthropogenic impacts to streams; consequently there is a high concentration of mitigation projects in the mountaintop mining/valley fill region. Projects are typically outside mine boundaries and sites are selected at the discretion of the West Virginia Department of Environmental Protection. This dissertation evaluated current in-stream, natural channel design (NCD) structures and prioritized future project locations. First, we assessed the Little Coal River, which is one of the largest physical restoration projects in the state. The Little Coal drains 994 km2 with extensive historic and contemporary coal mining. The objectives of …


Land Use/Land Cover Changes And Regional Climate Over The Loess Plateau During 2001-2009 – Part I. Observed Evidences, Rezaul Mahmood Jan 2015

Land Use/Land Cover Changes And Regional Climate Over The Loess Plateau During 2001-2009 – Part I. Observed Evidences, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.


Radiocarbon Dating Of Late Quaternary Sediments Using Fossil Gastropod Shells, Jeffrey S. Pigati, John P. Mcgeehin, Daniel R. Muhs Jan 2015

Radiocarbon Dating Of Late Quaternary Sediments Using Fossil Gastropod Shells, Jeffrey S. Pigati, John P. Mcgeehin, Daniel R. Muhs

United States Geological Survey: Staff Publications

Terrestrial gastropods are one of the most successful groups of organisms on Earth. Their distribution includes all continents except Antarctica, and they occupy exceptionally diverse habitats, from marshes and wet meadows to alpine forests and Arctic tundra. Their shells are also commonly preserved in Quaternary deposits and potentially could be used for 14C dating. However, terrestrial gastropods are known to ingest limestone and incorporate the old carbon in their shells, resulting in apparent ages that are often too old. Recent studies have shown that many small (<1 cm diameter) terrestrial gastropods avoid this “limestone problem” even when living in areas in which carbonate rocks are readily available. However, the shells must also behave as closed systems with respect to carbon if their ages are to be considered reliable. Our latest work has been aimed at testing if small gastropod shells do, in fact, remain closed systems in late Quaternary deposits over a wide array of climate conditions across North America. Our results demonstrate that ages derived from Succineidae shells are identical to wood and charcoal ages in loess in Alaska, glacial deposits in the upper Midwest, loess in the Great Plains, and paleowetlands in the desert southwest. Moreover, Succineidae shell ages routinely fall within permitted limits set by stratigraphic boundaries, require less interpretation than humic acid ages that are commonly used in loess studies, can provide additional stratigraphic coverage to previous dating efforts, and maintain stratigraphic order more often than luminescence ages from the same stratigraphic intervals. Thus, we conclude that fossil Succineidae shells, and shells of a few other small gastropods, can be used for 14C dating regardless of the local lithology, past climate, or environmental …