Alaskan soil carbon stocks: spatial variability and dependence on environmental factors
The direction and magnitude of soil organic carbon (SOC) changes in response to climate change depend on the spatial and vertical distributions of SOC. We estimated spatially resolved SOC stocks from surface to C horizon, distinguishing active-layer and permafrost-layer stocks, based on geospatial a...
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ftdoajarticles:oai:doaj.org/article:04c4e25253344fd09e1630383103248f 2023-05-15T17:55:52+02:00 Alaskan soil carbon stocks: spatial variability and dependence on environmental factors U. Mishra W. J. Riley 2012-09-01T00:00:00Z https://doi.org/10.5194/bg-9-3637-2012 https://doaj.org/article/04c4e25253344fd09e1630383103248f EN eng Copernicus Publications http://www.biogeosciences.net/9/3637/2012/bg-9-3637-2012.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-9-3637-2012 1726-4170 1726-4189 https://doaj.org/article/04c4e25253344fd09e1630383103248f Biogeosciences, Vol 9, Iss 9, Pp 3637-3645 (2012) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2012 ftdoajarticles https://doi.org/10.5194/bg-9-3637-2012 2022-12-31T14:30:12Z The direction and magnitude of soil organic carbon (SOC) changes in response to climate change depend on the spatial and vertical distributions of SOC. We estimated spatially resolved SOC stocks from surface to C horizon, distinguishing active-layer and permafrost-layer stocks, based on geospatial analysis of 472 soil profiles and spatially referenced environmental variables for Alaska. Total Alaska state-wide SOC stock was estimated to be 77 Pg, with 61% in the active-layer, 27% in permafrost, and 12% in non-permafrost soils. Prediction accuracy was highest for the active-layer as demonstrated by highest ratio of performance to deviation (1.5). Large spatial variability was predicted, with whole-profile, active-layer, and permafrost-layer stocks ranging from 1–296 kg C m −2 , 2–166 kg m −2 , and 0–232 kg m −2 , respectively. Temperature and soil wetness were found to be primary controllers of whole-profile, active-layer, and permafrost-layer SOC stocks. Secondary controllers, in order of importance, were found to be land cover type, topographic attributes, and bedrock geology. The observed importance of soil wetness rather than precipitation on SOC stocks implies that the poor representation of high-latitude soil wetness in Earth system models may lead to large uncertainty in predicted SOC stocks under future climate change scenarios. Under strict caveats described in the text and assuming temperature changes from the A1B Intergovernmental Panel on Climate Change emissions scenario, our geospatial model indicates that the equilibrium average 2100 Alaska active-layer depth could deepen by 11 cm, resulting in a thawing of 13 Pg C currently in permafrost. The equilibrium SOC loss associated with this warming would be highest under continuous permafrost (31%), followed by discontinuous (28%), isolated (24.3%), and sporadic (23.6%) permafrost areas. Our high-resolution mapping of soil carbon stock reveals the potential vulnerability of high-latitude soil carbon and can be used as a basis for future studies of ... Article in Journal/Newspaper permafrost Alaska Directory of Open Access Journals: DOAJ Articles Biogeosciences 9 9 3637 3645 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 U. Mishra W. J. Riley Alaskan soil carbon stocks: spatial variability and dependence on environmental factors |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
The direction and magnitude of soil organic carbon (SOC) changes in response to climate change depend on the spatial and vertical distributions of SOC. We estimated spatially resolved SOC stocks from surface to C horizon, distinguishing active-layer and permafrost-layer stocks, based on geospatial analysis of 472 soil profiles and spatially referenced environmental variables for Alaska. Total Alaska state-wide SOC stock was estimated to be 77 Pg, with 61% in the active-layer, 27% in permafrost, and 12% in non-permafrost soils. Prediction accuracy was highest for the active-layer as demonstrated by highest ratio of performance to deviation (1.5). Large spatial variability was predicted, with whole-profile, active-layer, and permafrost-layer stocks ranging from 1–296 kg C m −2 , 2–166 kg m −2 , and 0–232 kg m −2 , respectively. Temperature and soil wetness were found to be primary controllers of whole-profile, active-layer, and permafrost-layer SOC stocks. Secondary controllers, in order of importance, were found to be land cover type, topographic attributes, and bedrock geology. The observed importance of soil wetness rather than precipitation on SOC stocks implies that the poor representation of high-latitude soil wetness in Earth system models may lead to large uncertainty in predicted SOC stocks under future climate change scenarios. Under strict caveats described in the text and assuming temperature changes from the A1B Intergovernmental Panel on Climate Change emissions scenario, our geospatial model indicates that the equilibrium average 2100 Alaska active-layer depth could deepen by 11 cm, resulting in a thawing of 13 Pg C currently in permafrost. The equilibrium SOC loss associated with this warming would be highest under continuous permafrost (31%), followed by discontinuous (28%), isolated (24.3%), and sporadic (23.6%) permafrost areas. Our high-resolution mapping of soil carbon stock reveals the potential vulnerability of high-latitude soil carbon and can be used as a basis for future studies of ... |
format |
Article in Journal/Newspaper |
author |
U. Mishra W. J. Riley |
author_facet |
U. Mishra W. J. Riley |
author_sort |
U. Mishra |
title |
Alaskan soil carbon stocks: spatial variability and dependence on environmental factors |
title_short |
Alaskan soil carbon stocks: spatial variability and dependence on environmental factors |
title_full |
Alaskan soil carbon stocks: spatial variability and dependence on environmental factors |
title_fullStr |
Alaskan soil carbon stocks: spatial variability and dependence on environmental factors |
title_full_unstemmed |
Alaskan soil carbon stocks: spatial variability and dependence on environmental factors |
title_sort |
alaskan soil carbon stocks: spatial variability and dependence on environmental factors |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/bg-9-3637-2012 https://doaj.org/article/04c4e25253344fd09e1630383103248f |
genre |
permafrost Alaska |
genre_facet |
permafrost Alaska |
op_source |
Biogeosciences, Vol 9, Iss 9, Pp 3637-3645 (2012) |
op_relation |
http://www.biogeosciences.net/9/3637/2012/bg-9-3637-2012.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-9-3637-2012 1726-4170 1726-4189 https://doaj.org/article/04c4e25253344fd09e1630383103248f |
op_doi |
https://doi.org/10.5194/bg-9-3637-2012 |
container_title |
Biogeosciences |
container_volume |
9 |
container_issue |
9 |
container_start_page |
3637 |
op_container_end_page |
3645 |
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1766163899646738432 |