Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake
This study investigated the microbial ecology of Pony Lake, Antarctica. The main objectives of this research were to 1) characterize physicochemical parameters in Pony Lake during the transition from ice covered to ice free, 2) highlight seasonal and inter-seasonal alterations in lake parameters, 3)...
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Montana State University - Bozeman, College of Agriculture
2009
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ftmontanastateu:oai:scholarworks.montana.edu:1/1178 2023-05-15T13:54:59+02:00 Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake Dieser, Markus Chairperson, Graduate Committee: John C. Priscu; Christine Foreman (co-chair) Antarctica 2009 application/pdf https://scholarworks.montana.edu/xmlui/handle/1/1178 en eng Montana State University - Bozeman, College of Agriculture https://scholarworks.montana.edu/xmlui/handle/1/1178 Copyright 2009 by Markus Dieser Microorganisms Water Organic compounds Dissertation 2009 ftmontanastateu 2022-06-06T07:25:51Z This study investigated the microbial ecology of Pony Lake, Antarctica. The main objectives of this research were to 1) characterize physicochemical parameters in Pony Lake during the transition from ice covered to ice free, 2) highlight seasonal and inter-seasonal alterations in lake parameters, 3) relate the physicochemical conditions in the ice and water column to microbial processes and community structure, 4) characterize the effects of phototransformation of dissolved organic matter (DOM) on its bioavailability to bacteria, and 5) demonstrate the role of carotenoid pigments in protecting cells against environmental stresses. Also included are results from three McMurdo Dry Valley lakes on the survivability of microbes encapsulated within the lake ice covers. The results of this study highlight the sensitivity of Antarctic environments and the close coupling of environmental conditions and biological processes. Inter-seasonal differences in weather conditions and snow accumulation strongly affected the physicochemistry of this lacustrine system. Biological processes were closely tied to the physicochemical lake conditions. As a consequence planktonic abundances, production rates, and community structure evolved distinctly in each year. Bacterial production was regulated by the quality of DOM. Whereas nutrient availability appeared to play a minor role in eutrophic Pony Lake water, it became more critical for microbial communities found within the ice column of Antarctic lakes. Especially in the ice cover of the McMurdo Dry Valley lakes, enhanced microbial diversity and survivability was associated with particles (nutrient enriched micro-zones) within an otherwise ultra-oligotrophic habitat. In Pony Lake ice, microbial activity and community structure differed with respect to different strata within the ice column, induced by freeze-concentration of solutes, bioavailability of DOM, and oxygen gradients. A comparison of carotenoid pigmented and non-pigmented heterotrophic bacteria indicated that pigmentation ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctica Montana State University (MSU): ScholarWorks Antarctic Pony Lake ENVELOPE(166.150,166.150,-77.550,-77.550) |
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collection |
Montana State University (MSU): ScholarWorks |
op_collection_id |
ftmontanastateu |
language |
English |
topic |
Microorganisms Water Organic compounds |
spellingShingle |
Microorganisms Water Organic compounds Dieser, Markus Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake |
topic_facet |
Microorganisms Water Organic compounds |
description |
This study investigated the microbial ecology of Pony Lake, Antarctica. The main objectives of this research were to 1) characterize physicochemical parameters in Pony Lake during the transition from ice covered to ice free, 2) highlight seasonal and inter-seasonal alterations in lake parameters, 3) relate the physicochemical conditions in the ice and water column to microbial processes and community structure, 4) characterize the effects of phototransformation of dissolved organic matter (DOM) on its bioavailability to bacteria, and 5) demonstrate the role of carotenoid pigments in protecting cells against environmental stresses. Also included are results from three McMurdo Dry Valley lakes on the survivability of microbes encapsulated within the lake ice covers. The results of this study highlight the sensitivity of Antarctic environments and the close coupling of environmental conditions and biological processes. Inter-seasonal differences in weather conditions and snow accumulation strongly affected the physicochemistry of this lacustrine system. Biological processes were closely tied to the physicochemical lake conditions. As a consequence planktonic abundances, production rates, and community structure evolved distinctly in each year. Bacterial production was regulated by the quality of DOM. Whereas nutrient availability appeared to play a minor role in eutrophic Pony Lake water, it became more critical for microbial communities found within the ice column of Antarctic lakes. Especially in the ice cover of the McMurdo Dry Valley lakes, enhanced microbial diversity and survivability was associated with particles (nutrient enriched micro-zones) within an otherwise ultra-oligotrophic habitat. In Pony Lake ice, microbial activity and community structure differed with respect to different strata within the ice column, induced by freeze-concentration of solutes, bioavailability of DOM, and oxygen gradients. A comparison of carotenoid pigmented and non-pigmented heterotrophic bacteria indicated that pigmentation ... |
author2 |
Chairperson, Graduate Committee: John C. Priscu; Christine Foreman (co-chair) |
format |
Doctoral or Postdoctoral Thesis |
author |
Dieser, Markus |
author_facet |
Dieser, Markus |
author_sort |
Dieser, Markus |
title |
Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake |
title_short |
Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake |
title_full |
Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake |
title_fullStr |
Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake |
title_full_unstemmed |
Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake |
title_sort |
ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake |
publisher |
Montana State University - Bozeman, College of Agriculture |
publishDate |
2009 |
url |
https://scholarworks.montana.edu/xmlui/handle/1/1178 |
op_coverage |
Antarctica |
long_lat |
ENVELOPE(166.150,166.150,-77.550,-77.550) |
geographic |
Antarctic Pony Lake |
geographic_facet |
Antarctic Pony Lake |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_relation |
https://scholarworks.montana.edu/xmlui/handle/1/1178 |
op_rights |
Copyright 2009 by Markus Dieser |
_version_ |
1766261194553819136 |