Active heterotrophic microbial communities from polar desert soils of the Canadian High Arctic

• Author / Creator

  Taghavimehr,Elham

• Polar warming will lead to increased labile organic carbon in Arctic soils, both from the release of organic carbon stored in permafrost and increased plant production. The impact of increasing organic carbon on Arctic soil microbial community composition and activity is of great interest because microbial decomposition of Arctic soil organic carbon is a potential major source of CO2 to the atmosphere. I determined the activity and composition of the active heterotrophic bacteria in soil cores of the Canadian High Arctic by stable isotope probing (SIP) with a labile organic carbon analogue, 13C-labeled algal lysate. The activity, measured as CO2 production rate, was significantly higher with substrate added compared to the controls. There was a significant decrease in diversity and a shift in community composition following addition of labile carbon. These results suggest only a few groups within the community are active and responsive to increased complex organic carbon.

• Subjects / Keywords

  • Permafrost
  • Arctic microbiology
  • Stable isotope probing
  • Carbon cycling

• Graduation date

  Fall 2012

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3XK84Z7Q

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.