Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw
Amplified Arctic warming could thaw 25% of the permafrost area by 2100, exposing vast amounts of currently fixed organic carbon to microbially mediated decomposition and release of greenhouse gasses through soil organic matter (SOM) respiration. We performed time-series incubation experiments with H...
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Online Access: | https://hdl.handle.net/20.500.11937/11127 https://doi.org/10.1111/j.1462-2920.2011.02489.x |
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ftcurtin:oai:espace.curtin.edu.au:20.500.11937/11127 2023-06-11T04:09:50+02:00 Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw Coolen, Marco van de Giessen, J. Zhu, E. Wuchter, C. 2011 restricted https://hdl.handle.net/20.500.11937/11127 https://doi.org/10.1111/j.1462-2920.2011.02489.x unknown http://hdl.handle.net/20.500.11937/11127 doi:10.1111/j.1462-2920.2011.02489.x Journal Article 2011 ftcurtin https://doi.org/20.500.11937/1112710.1111/j.1462-2920.2011.02489.x 2023-05-30T19:25:42Z Amplified Arctic warming could thaw 25% of the permafrost area by 2100, exposing vast amounts of currently fixed organic carbon to microbially mediated decomposition and release of greenhouse gasses through soil organic matter (SOM) respiration. We performed time-series incubation experiments with Holocene permafrost soils at 4°C for up to 11 days to determine changes in exoenzyme activities (EEAs) (i.e. phosphatase, β-glucosidase, aminopeptidase) as a measure for the bioavailability of SOM in response to permafrost thaw. We also profiled SSU rRNA transcripts to follow the qualitative and quantitative changes in viable prokaryotes and eukaryotes during incubation. EEA, amount of rRNA transcripts and microbial community structures differed substantially between the various soil intervals in response to thaw: after 11 days of incubation, the active layer became slightly depleted in C and P and harboured bacterial phyla indicative of more oligotrophic conditions (Acidobacteria).A fast response in phosphatase and β-glucosidase upon thaw, and a predominance of active copiotrophic Bacteroidetes, showed that the upper permafrost plate serves as storage of easily degradable carbon derived from the overlying thawed active layer during summer. EEA profiles and microbial community dynamics furthermore suggest that the deeper and older permafrost intervals mainly contain recalcitrant SOM, and that extracellular soil-bound exoenzymes play a role in the initial cleavage of biopolymers, which could kick-start microbial growth upon thaw. Basidiomycetous fungi and Candidate Subdivision OP5 bacteria were the first to respond in freshly thawed deeper permafrost intervals, and might play an important role in the decomposition of recalcitrant SOM to release more labile substrates to support the major bacterial phyla (β-Proteobacteria, Actinobacteria, Firmicutes), which predominated thereafter. Article in Journal/Newspaper Arctic permafrost Curtin University: espace Arctic Environmental Microbiology 13 8 2299 2314 |
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Curtin University: espace |
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Amplified Arctic warming could thaw 25% of the permafrost area by 2100, exposing vast amounts of currently fixed organic carbon to microbially mediated decomposition and release of greenhouse gasses through soil organic matter (SOM) respiration. We performed time-series incubation experiments with Holocene permafrost soils at 4°C for up to 11 days to determine changes in exoenzyme activities (EEAs) (i.e. phosphatase, β-glucosidase, aminopeptidase) as a measure for the bioavailability of SOM in response to permafrost thaw. We also profiled SSU rRNA transcripts to follow the qualitative and quantitative changes in viable prokaryotes and eukaryotes during incubation. EEA, amount of rRNA transcripts and microbial community structures differed substantially between the various soil intervals in response to thaw: after 11 days of incubation, the active layer became slightly depleted in C and P and harboured bacterial phyla indicative of more oligotrophic conditions (Acidobacteria).A fast response in phosphatase and β-glucosidase upon thaw, and a predominance of active copiotrophic Bacteroidetes, showed that the upper permafrost plate serves as storage of easily degradable carbon derived from the overlying thawed active layer during summer. EEA profiles and microbial community dynamics furthermore suggest that the deeper and older permafrost intervals mainly contain recalcitrant SOM, and that extracellular soil-bound exoenzymes play a role in the initial cleavage of biopolymers, which could kick-start microbial growth upon thaw. Basidiomycetous fungi and Candidate Subdivision OP5 bacteria were the first to respond in freshly thawed deeper permafrost intervals, and might play an important role in the decomposition of recalcitrant SOM to release more labile substrates to support the major bacterial phyla (β-Proteobacteria, Actinobacteria, Firmicutes), which predominated thereafter. |
format |
Article in Journal/Newspaper |
author |
Coolen, Marco van de Giessen, J. Zhu, E. Wuchter, C. |
spellingShingle |
Coolen, Marco van de Giessen, J. Zhu, E. Wuchter, C. Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw |
author_facet |
Coolen, Marco van de Giessen, J. Zhu, E. Wuchter, C. |
author_sort |
Coolen, Marco |
title |
Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw |
title_short |
Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw |
title_full |
Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw |
title_fullStr |
Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw |
title_full_unstemmed |
Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw |
title_sort |
bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw |
publishDate |
2011 |
url |
https://hdl.handle.net/20.500.11937/11127 https://doi.org/10.1111/j.1462-2920.2011.02489.x |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic permafrost |
genre_facet |
Arctic permafrost |
op_relation |
http://hdl.handle.net/20.500.11937/11127 doi:10.1111/j.1462-2920.2011.02489.x |
op_doi |
https://doi.org/20.500.11937/1112710.1111/j.1462-2920.2011.02489.x |
container_title |
Environmental Microbiology |
container_volume |
13 |
container_issue |
8 |
container_start_page |
2299 |
op_container_end_page |
2314 |
_version_ |
1768383852510707712 |