Diatom-inferred records of paleo-climate and paleo-hydrogeology from lakes in regions of different climate

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dc.contributor Ward, G. Milton
dc.contributor Findlay, Robert H.
dc.contributor Benstead, Jonathan P.
dc.contributor Dahm, Clifford N.
dc.contributor.advisor Ward, Amelia K.
dc.contributor.author Hodgson, Jay York Seabright
dc.date.accessioned 2017-02-28T22:20:42Z
dc.date.available 2017-02-28T22:20:42Z
dc.date.issued 2009
dc.identifier.other u0015_0000001_0000059
dc.identifier.other Hodgson_alatus_0004D_10092
dc.identifier.uri https://ir.ua.edu/handle/123456789/566
dc.description Electronic Thesis or Dissertation
dc.description.abstract I comparatively investigated mid-to-late Holocene paleo-climate and paleo-hydrogeology in three regions with different climates (Alaska, New Mexico, and Alabama) using diatom frustules as the primary proxy sampled from lake sediment cores. This cross-regional research differs from previous paleo-limnology syntheses because it was designed a priori to simultaneously decipher differential environmental conditions using uniform measurements of the same proxy types with equal environmental sensitivities across spatial scales. Data were analyzed with a combination of multivariate ordination and time series bandwidth analysis to identify significant bifurcation points between periods of changing environmental conditions. Each study region demonstrated different environmental changes through time. Diatom community dynamics in Alaska were significantly correlated with temperatures, indicating that diatom community structure is a validated temperature change surrogate. In New Mexico, diatom dynamics were significantly correlated with both precipitation and solar intensity, suggesting that diatoms are validated surrogates of solar-modulated drought. Additionally, the diatoms indicated that the study lake was susceptible to drought-induced acidification. In Alabama, the combination of diatoms and sedimentary organic matter elucidated oxbow lake evolution and fluctuations in coastal plain water tables. These changes were potentially caused by alterations in precipitation and eustatic sea levels following the last glaciation. Similar interpretations of mid-Holocene hydrogeology have been reported elsewhere in the coastal plain. This cross-regional research demonstrated differential proxy responses between each climate region. More importantly, it also suggested reasons why uniform methods elucidated varying responses across broad spatial scales. Global climate change has the potential to affect different regional climates very differently from each other. My intersite research indicated that each region did not capture a ubiquitous global climate pressure. Instead, each region experienced asynchronous climate changes through time. This research is an important first step and a valuable approach in discerning climate change responses among different regions that could, subsequently, be applied more broadly across other regions and lead to improved climate change analyses.
dc.format.extent 201 p.
dc.format.medium electronic
dc.format.mimetype application/pdf
dc.language English
dc.language.iso en_US
dc.publisher University of Alabama Libraries
dc.relation.ispartof The University of Alabama Electronic Theses and Dissertations
dc.relation.hasversion born digital
dc.rights All rights reserved by the author unless otherwise indicated.
dc.subject.other Biology, Limnology
dc.title Diatom-inferred records of paleo-climate and paleo-hydrogeology from lakes in regions of different climate
dc.type thesis
dc.type text
etdms.degree.department University of Alabama. Dept. of Biological Sciences
etdms.degree.discipline Biological Sciences
etdms.degree.grantor The University of Alabama
etdms.degree.level doctoral
etdms.degree.name Ph.D.

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