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Microbial Community Changes in 26,500-Year-Old Thawing Permafrost

Northern permafrost soils store more than half of the global soil carbon. Frozen for at least two consecutive years, but often for millennia, permafrost temperatures have increased drastically in the last decades. The resulting thermal erosion leads not only to gradual thaw, resulting in an increase...

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Autores principales: Scheel, Maria, Zervas, Athanasios, Jacobsen, Carsten S., Christensen, Torben R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8988141/
https://www.ncbi.nlm.nih.gov/pubmed/35401488
http://dx.doi.org/10.3389/fmicb.2022.787146
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author Scheel, Maria
Zervas, Athanasios
Jacobsen, Carsten S.
Christensen, Torben R.
author_facet Scheel, Maria
Zervas, Athanasios
Jacobsen, Carsten S.
Christensen, Torben R.
author_sort Scheel, Maria
collection PubMed
description Northern permafrost soils store more than half of the global soil carbon. Frozen for at least two consecutive years, but often for millennia, permafrost temperatures have increased drastically in the last decades. The resulting thermal erosion leads not only to gradual thaw, resulting in an increase of seasonally thawing soil thickness, but also to abrupt thaw events, such as sudden collapses of the soil surface. These could affect 20% of the permafrost zone and half of its organic carbon, increasing accessibility for deeper rooting vegetation and microbial decomposition into greenhouse gases. Knowledge gaps include the impact of permafrost thaw on the soil microfauna as well as key taxa to change the microbial mineralization of ancient permafrost carbon stocks during erosion. Here, we present the first sequencing study of an abrupt permafrost erosion microbiome in Northeast Greenland, where a thermal erosion gully collapsed in the summer of 2018, leading to the thawing of 26,500-year-old permafrost material. We investigated which soil parameters (pH, soil carbon content, age and moisture, organic and mineral horizons, and permafrost layers) most significantly drove changes of taxonomic diversity and the abundance of soil microorganisms in two consecutive years of intense erosion. Sequencing of the prokaryotic 16S rRNA and fungal ITS2 gene regions at finely scaled depth increments revealed decreasing alpha diversity with depth, soil age, and pH. The most significant drivers of variation were found in the soil age, horizons, and permafrost layer for prokaryotic and fungal beta diversity. Permafrost was mainly dominated by Proteobacteria and Firmicutes, with Polaromonas identified as the most abundant taxon. Thawed permafrost samples indicated increased abundance of several copiotrophic phyla, such as Bacteroidia, suggesting alterations of carbon utilization pathways within eroding permafrost.
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spelling pubmed-89881412022-04-08 Microbial Community Changes in 26,500-Year-Old Thawing Permafrost Scheel, Maria Zervas, Athanasios Jacobsen, Carsten S. Christensen, Torben R. Front Microbiol Microbiology Northern permafrost soils store more than half of the global soil carbon. Frozen for at least two consecutive years, but often for millennia, permafrost temperatures have increased drastically in the last decades. The resulting thermal erosion leads not only to gradual thaw, resulting in an increase of seasonally thawing soil thickness, but also to abrupt thaw events, such as sudden collapses of the soil surface. These could affect 20% of the permafrost zone and half of its organic carbon, increasing accessibility for deeper rooting vegetation and microbial decomposition into greenhouse gases. Knowledge gaps include the impact of permafrost thaw on the soil microfauna as well as key taxa to change the microbial mineralization of ancient permafrost carbon stocks during erosion. Here, we present the first sequencing study of an abrupt permafrost erosion microbiome in Northeast Greenland, where a thermal erosion gully collapsed in the summer of 2018, leading to the thawing of 26,500-year-old permafrost material. We investigated which soil parameters (pH, soil carbon content, age and moisture, organic and mineral horizons, and permafrost layers) most significantly drove changes of taxonomic diversity and the abundance of soil microorganisms in two consecutive years of intense erosion. Sequencing of the prokaryotic 16S rRNA and fungal ITS2 gene regions at finely scaled depth increments revealed decreasing alpha diversity with depth, soil age, and pH. The most significant drivers of variation were found in the soil age, horizons, and permafrost layer for prokaryotic and fungal beta diversity. Permafrost was mainly dominated by Proteobacteria and Firmicutes, with Polaromonas identified as the most abundant taxon. Thawed permafrost samples indicated increased abundance of several copiotrophic phyla, such as Bacteroidia, suggesting alterations of carbon utilization pathways within eroding permafrost. Frontiers Media S.A. 2022-03-24 /pmc/articles/PMC8988141/ /pubmed/35401488 http://dx.doi.org/10.3389/fmicb.2022.787146 Text en Copyright © 2022 Scheel, Zervas, Jacobsen and Christensen. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Scheel, Maria
Zervas, Athanasios
Jacobsen, Carsten S.
Christensen, Torben R.
Microbial Community Changes in 26,500-Year-Old Thawing Permafrost
title Microbial Community Changes in 26,500-Year-Old Thawing Permafrost
title_full Microbial Community Changes in 26,500-Year-Old Thawing Permafrost
title_fullStr Microbial Community Changes in 26,500-Year-Old Thawing Permafrost
title_full_unstemmed Microbial Community Changes in 26,500-Year-Old Thawing Permafrost
title_short Microbial Community Changes in 26,500-Year-Old Thawing Permafrost
title_sort microbial community changes in 26,500-year-old thawing permafrost
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8988141/
https://www.ncbi.nlm.nih.gov/pubmed/35401488
http://dx.doi.org/10.3389/fmicb.2022.787146
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