Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities
Microbial community composition plays a vital role in soil biogeochemical cycling. Information that explains the biogeography of microorganisms is consequently necessary for predicting the timing and magnitude of important ecosystem services mediated by soil biota, such as decomposition and nutrient...
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Virginia Tech
2014
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ftvirginiatec:oai:vtechworks.lib.vt.edu:10919/64417 2024-05-19T07:32:23+00:00 Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities Geyer, Kevin M. Biological Sciences Barrett, John E. Strahm, Brian D. Belden, Lisa K. Webster, Jackson R. 2014-07-15 ETD application/pdf http://hdl.handle.net/10919/64417 unknown Virginia Tech vt_gsexam:3372 http://hdl.handle.net/10919/64417 In Copyright http://rightsstatements.org/vocab/InC/1.0/ microbial ecology biogeography productivity/diversity theory biogeochemistry McMurdo Dry Valleys Dissertation 2014 ftvirginiatec 2024-05-01T01:15:11Z Microbial community composition plays a vital role in soil biogeochemical cycling. Information that explains the biogeography of microorganisms is consequently necessary for predicting the timing and magnitude of important ecosystem services mediated by soil biota, such as decomposition and nutrient cycling. Theory developed to explain patterns in plant and animal distributions such as the prevalent relationship between ecosystem productivity and diversity may be successfully extended to microbial systems and accelerate an emerging ecological understanding of the "unseen majority." These considerations suggest a need to define the important mechanisms which affect microbial biogeography as well as the sensitivity of community structure/function to changing climatic or environmental conditions. To this end, my dissertation covers three data chapters in which I have 1) examined patterns in bacterial biogeography using gradients of environmental severity and productivity to identify changes in community diversity (e.g. taxonomic richness) and structure (e.g. similarity); 2) detected potential bacterial ecotypes associated with distinct soil habitats such as those of high alkalinity or electrical conductivity and; 3) measured environmental controls over the function (e.g. primary production, exoenzyme activity) of soil organisms in an environment of severe environmental limitations. Sampling was performed in the polar desert of Antarctica's McMurdo Dry Valleys, a model ecosystem which hosts microbially-dominated soil foodwebs and displays heterogeneously distributed soil properties across the landscape. Results for Chapter 2 indicate differential effects of resource availability and geochemical severity on bacterial communities, with a significant productivity-diversity relationship that plateaus near the highest observed concentrations of the limiting resource organic carbon (0.30mg C/g soil). Geochemical severity (e.g. pH, electrical conductivity) primarily affected bacterial community similarity and successfully ... Doctoral or Postdoctoral Thesis Antarc* Antarctic McMurdo Dry Valleys polar desert VTechWorks (VirginiaTech) |
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VTechWorks (VirginiaTech) |
op_collection_id |
ftvirginiatec |
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topic |
microbial ecology biogeography productivity/diversity theory biogeochemistry McMurdo Dry Valleys |
spellingShingle |
microbial ecology biogeography productivity/diversity theory biogeochemistry McMurdo Dry Valleys Geyer, Kevin M. Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities |
topic_facet |
microbial ecology biogeography productivity/diversity theory biogeochemistry McMurdo Dry Valleys |
description |
Microbial community composition plays a vital role in soil biogeochemical cycling. Information that explains the biogeography of microorganisms is consequently necessary for predicting the timing and magnitude of important ecosystem services mediated by soil biota, such as decomposition and nutrient cycling. Theory developed to explain patterns in plant and animal distributions such as the prevalent relationship between ecosystem productivity and diversity may be successfully extended to microbial systems and accelerate an emerging ecological understanding of the "unseen majority." These considerations suggest a need to define the important mechanisms which affect microbial biogeography as well as the sensitivity of community structure/function to changing climatic or environmental conditions. To this end, my dissertation covers three data chapters in which I have 1) examined patterns in bacterial biogeography using gradients of environmental severity and productivity to identify changes in community diversity (e.g. taxonomic richness) and structure (e.g. similarity); 2) detected potential bacterial ecotypes associated with distinct soil habitats such as those of high alkalinity or electrical conductivity and; 3) measured environmental controls over the function (e.g. primary production, exoenzyme activity) of soil organisms in an environment of severe environmental limitations. Sampling was performed in the polar desert of Antarctica's McMurdo Dry Valleys, a model ecosystem which hosts microbially-dominated soil foodwebs and displays heterogeneously distributed soil properties across the landscape. Results for Chapter 2 indicate differential effects of resource availability and geochemical severity on bacterial communities, with a significant productivity-diversity relationship that plateaus near the highest observed concentrations of the limiting resource organic carbon (0.30mg C/g soil). Geochemical severity (e.g. pH, electrical conductivity) primarily affected bacterial community similarity and successfully ... |
author2 |
Biological Sciences Barrett, John E. Strahm, Brian D. Belden, Lisa K. Webster, Jackson R. |
format |
Doctoral or Postdoctoral Thesis |
author |
Geyer, Kevin M. |
author_facet |
Geyer, Kevin M. |
author_sort |
Geyer, Kevin M. |
title |
Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities |
title_short |
Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities |
title_full |
Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities |
title_fullStr |
Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities |
title_full_unstemmed |
Environmental Controls Over the Distribution and Function of Antarctic Soil Microbial Communities |
title_sort |
environmental controls over the distribution and function of antarctic soil microbial communities |
publisher |
Virginia Tech |
publishDate |
2014 |
url |
http://hdl.handle.net/10919/64417 |
genre |
Antarc* Antarctic McMurdo Dry Valleys polar desert |
genre_facet |
Antarc* Antarctic McMurdo Dry Valleys polar desert |
op_relation |
vt_gsexam:3372 http://hdl.handle.net/10919/64417 |
op_rights |
In Copyright http://rightsstatements.org/vocab/InC/1.0/ |
_version_ |
1799470419832471552 |