Relationships between greenhouse gas production and landscape position during short-term permafrost thaw under anaerobic conditions in the Lena Delta
<p>Soils in the permafrost region have acted as carbon sinks for thousands of years. As a result of global warming, permafrost soils are thawing and will potentially release greenhouse gases (GHGs) such as methane (CH<span class="inline-formula"><sub>4</sub></spa...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-06-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/20/2049/2023/bg-20-2049-2023.pdf |
| Summary: | <p>Soils in the permafrost region have acted as carbon sinks
for thousands of years. As a result of global warming, permafrost soils are
thawing and will potentially release greenhouse gases (GHGs) such as methane
(CH<span class="inline-formula"><sub>4</sub></span>) and carbon dioxide (CO<span class="inline-formula"><sub>2</sub></span>). However, small-scale spatial
heterogeneities of GHG production have been neglected in previous incubation
studies. Here, we used an anaerobic incubation experiment to simulate
permafrost thaw along a transect from upland Yedoma to the floodplain on
Kurungnakh Island. Potential CO<span class="inline-formula"><sub>2</sub></span> and CH<span class="inline-formula"><sub>4</sub></span> production was measured
during incubation of the active layer and permafrost soils at 4
and 20 <span class="inline-formula"><sup>∘</sup></span>C, first for 60 d (approximate length of the growing
season) and then continuing for 1 year. An assessment of methanogen
abundance was performed in parallel for the first 60 d. Yedoma samples
from upland and slope cores remained in a lag phase during the growing
season simulation, while those located in the floodplain showed high
production of CH<span class="inline-formula"><sub>4</sub></span> (<span class="inline-formula">6.5×10<sup>3</sup></span> <span class="inline-formula">µ</span>g CH<span class="inline-formula"><sub>4</sub></span>-C g<span class="inline-formula"><sup>−1</sup></span> C) and
CO<span class="inline-formula"><sub>2</sub></span> (<span class="inline-formula">6.9×10<sup>3</sup></span> <span class="inline-formula">µ</span>g CO<span class="inline-formula"><sub>2</sub></span>-C g<span class="inline-formula"><sup>−1</sup></span> C) at 20 <span class="inline-formula"><sup>∘</sup></span>C. The
Yedoma samples from the permafrost layer started producing CH<span class="inline-formula"><sub>4</sub></span> after
6 months of incubation. We conclude that landscape position is a key
factor triggering CH<span class="inline-formula"><sub>4</sub></span> production during the growing season time on
Kurungnakh Island.</p> |
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| ISSN: | 1726-4170 1726-4189 |