MAPPING MICROBIAL SUBSTRATE UTILIZATION ACROSS A PERMAFROST THAW GRADIENT

Persistent Link:
http://hdl.handle.net/10150/612547
Title:
MAPPING MICROBIAL SUBSTRATE UTILIZATION ACROSS A PERMAFROST THAW GRADIENT
Author:
ANDERSON, DARYA NICOLE
Issue Date:
2016
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Permafrost thaw is likely to create a substantial positive feedback to climate change, as previously frozen organic carbon (OC) becomes available for biological metabolism and is released to the atmosphere. Microbes mediate transformation and release of formerly stored C, while also consuming recently fixed plant C and age stored C in the seasonally-thawed peat active layer. This biological activity releases carbon dioxide (CO2) and methane (CH4) to the atmosphere. To investigate microbial C cycling changes with permafrost thaw, we examined how microbial community C substrate degradation differed between two thaw features in Stordalen Mire, Sweden, located at the discontinuous southern edge of the permafrost zone. The progression of thaw results in increasing organic matter lability, shifting microbial community composition, and changing C gas emissions. However, the interrelationship of the population metabolism with the gas release remains unclear. We analyzed microbial C substrate utilization in bog and fen sites using Biolog Ecoplates and measurements of CH4 and CO2 production in anaerobic incubations of peat with select C substrate amendments. Overall, the results suggest that, with permafrost thaw, substrates for microbial carbon processing diversify, utilization of these substrates reaches a greater extent, and pathways of carbon degradation shift towards methanogenesis.
Type:
text; Electronic Thesis
Degree Name:
B.S.
Degree Level:
Bachelors
Degree Program:
Honors College; Soil, Water and Environmental Science
Degree Grantor:
University of Arizona
Advisor:
Rich, Virginia

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titleMAPPING MICROBIAL SUBSTRATE UTILIZATION ACROSS A PERMAFROST THAW GRADIENTen_US
dc.creatorANDERSON, DARYA NICOLEen
dc.contributor.authorANDERSON, DARYA NICOLEen
dc.date.issued2016-
dc.publisherThe University of Arizona.en
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en
dc.description.abstractPermafrost thaw is likely to create a substantial positive feedback to climate change, as previously frozen organic carbon (OC) becomes available for biological metabolism and is released to the atmosphere. Microbes mediate transformation and release of formerly stored C, while also consuming recently fixed plant C and age stored C in the seasonally-thawed peat active layer. This biological activity releases carbon dioxide (CO2) and methane (CH4) to the atmosphere. To investigate microbial C cycling changes with permafrost thaw, we examined how microbial community C substrate degradation differed between two thaw features in Stordalen Mire, Sweden, located at the discontinuous southern edge of the permafrost zone. The progression of thaw results in increasing organic matter lability, shifting microbial community composition, and changing C gas emissions. However, the interrelationship of the population metabolism with the gas release remains unclear. We analyzed microbial C substrate utilization in bog and fen sites using Biolog Ecoplates and measurements of CH4 and CO2 production in anaerobic incubations of peat with select C substrate amendments. Overall, the results suggest that, with permafrost thaw, substrates for microbial carbon processing diversify, utilization of these substrates reaches a greater extent, and pathways of carbon degradation shift towards methanogenesis.en
dc.typetexten
dc.typeElectronic Thesisen
thesis.degree.nameB.S.en
thesis.degree.levelBachelorsen
thesis.degree.disciplineHonors Collegeen
thesis.degree.disciplineSoil, Water and Environmental Scienceen
thesis.degree.grantorUniversity of Arizonaen
dc.contributor.advisorRich, Virginiaen
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