Show simple item record

dc.contributor.advisorChairperson, Graduate Committee: John C. Priscuen
dc.contributor.authorSantibanez-Avila, Pamela Alejandraen
dc.contributor.otherJoseph R. McConnell and John C. Priscu were co-authors of the article, 'A flow cytometric method to measure prokaryotic records in ice cores: an example from the Wais Divide drilling site' submitted to the journal 'Journal of glaciology: instruments and methods' which is contained within this dissertation.en
dc.contributor.otherMark Greenwood, Joseph R. McConnell and John C. Priscu were co-authors of the article, 'Prokaryotic concentration changes between the last glacial maximum and the early Holocene from the Wais Divide ice core' submitted to the journal 'Quaternary science reviews' which is contained within this dissertation.en
dc.contributor.otherAlexander B. Michaud, Trista J. Vick-Majors, Juliana D'Andrilli, Amy Chiuchiolo and John Priscu were co-authors of the article, 'Bacterial response to progressive freezing in perennially and seasonally ice-covered lakes' submitted to the journal 'Journal of geophysical research (JGR) biogeosciences' which is contained within this dissertation.en
dc.coverage.spatialBarrow (Alaska)en
dc.description.abstractMicrobial life can easily live without us; we, however, cannot survive without the global catalysis and environmental transformations it provides' (Falkowski et al., 2008). Despite of the key role of microbes on Earth, microbial community characteristics are not explicitly part of climate models because our understanding of their responses to long-term environmental and climatic processes is limited. In this study, I developed a Flow Cytometric protocol to access a long-term record of non-photosynthetic prokaryotic cell concentration archived in the West Antarctic Ice-Sheet (WAIS; chapter 2). The WD ice core was retrieved between 2009 and 2011 to a depth of 3,405 m, extending back to 68,000 before 1950. Once a 17,400 year-record of prokaryotic cell concentration was acquired, I investigated its temporal variability and patterns, determined the potential sources of prokaryotic cells between the Last Glacial Maximum and the early Holocene, and assessed the environmental factors that might have the largest influence on the prokaryotic response (chapter 3). The observed patterns in the prokaryotic record are linked to large-scale controls of the Southern Ocean and West Antarctica Ice-Sheet. The main research findings presented here about the first prokaryotic record are: (i) airborne prokaryotic cell concentration does respond to long-term climatic and environmental processes, (ii) the processes of deglaciation, sea level rise and sea-ice fluctuation were key; the abundance of prokaryotic cells covariate with ssNa and black carbon, and (iii) the prokaryotic cell record variate on millennial time scale with cycles of 1,490-years. In addition, I studied 'congelation ice' (i.e., ice forms as liquid water freezes) from ice-covered lakes to understand prokaryotic cell segregation between liquid and solid phases during the physical freezing process. Five mesocosm experiments were designed to understand prokaryotic responses to the progressive freezing in concert with field observations from ice-covered lakes from Barrow, Alaska. As a result of this last study (chapter 4), I concluded that prokaryotic cells are preferentially incorporated in the ice with segregation coefficients (K eff) between 0.8 - 4.4, which are higher than for major ions. Prokaryotic cells avoid rejection more effectively from the ice matrix.en
dc.publisherMontana State University - Bozeman, College of Agricultureen
dc.subject.lcshClimatic changesen
dc.titleFactors influecing the abundance of microorganisms in icy environmentsen
dc.title.alternativeFactors influencing the abundance of microorganisms in icy environmentsen
dc.rights.holderCopyright 2016 by Pamela Alejandra Santibanez-Avilaen, Graduate Committee: Cathy Whitlock; Mark Greenwood; Mark L. Skidmore.en Resources & Environmental Sciences.en
mus.relation.departmentLand Resources & Environmental Sciences.en_US

Files in this item


This item appears in the following Collection(s)

Show simple item record

MSU uses DSpace software, copyright © 2002-2017  Duraspace. For library collections that are not accessible, we are committed to providing reasonable accommodations and timely access to users with disabilities. For assistance, please submit an accessibility request for library material.