Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska
There is a substantial amount of carbon stored in the permafrost soils of boreal forest ecosystems, where it is currently protected from decomposition. The surface organic horizons insulate the deeper soil from variations in atmospheric temperature. The removal of these insulating horizons through c...
Published in: | Environmental Research Letters |
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Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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IOP Publishing
2016
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Subjects: | |
Online Access: | http://iopscience.iop.org/article/10.1088/1748-9326/8/4/045016 http://hdl.handle.net/2381/37489 https://doi.org/10.1088/1748-9326/8/4/045016 |
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ftleicester:oai:lra.le.ac.uk:2381/37489 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
University of Leicester: Leicester Research Archive (LRA) |
op_collection_id |
ftleicester |
language |
English |
description |
There is a substantial amount of carbon stored in the permafrost soils of boreal forest ecosystems, where it is currently protected from decomposition. The surface organic horizons insulate the deeper soil from variations in atmospheric temperature. The removal of these insulating horizons through consumption by fire increases the vulnerability of permafrost to thaw, and the carbon stored in permafrost to decomposition. In this study we ask how warming and fire regime may influence spatial and temporal changes in active layer and carbon dynamics across a boreal forest landscape in interior Alaska. To address this question, we (1) developed and tested a predictive model of the effect of fire severity on soil organic horizons that depends on landscape-level conditions and (2) used this model to evaluate the long-term consequences of warming and changes in fire regime on active layer and soil carbon dynamics of black spruce forests across interior Alaska. The predictive model of fire severity, designed from the analysis of field observations, reproduces the effect of local topography (landform category, the slope angle and aspect and flow accumulation), weather conditions (drought index, soil moisture) and fire characteristics (day of year and size of the fire) on the reduction of the organic layer caused by fire. The integration of the fire severity model into an ecosystem process-based model allowed us to document the relative importance and interactions among local topography, fire regime and climate warming on active layer and soil carbon dynamics. Lowlands were more resistant to severe fires and climate warming, showing smaller increases in active layer thickness and soil carbon loss compared to drier flat uplands and slopes. In simulations that included the effects of both warming and fire at the regional scale, fire was primarily responsible for a reduction in organic layer thickness of 0.06 m on average by 2100 that led to an increase in active layer thickness of 1.1 m on average by 2100. The combination of warming and fire led to a simulated cumulative loss of 9.6 kgC m−2 on average by 2100. Our analysis suggests that ecosystem carbon storage in boreal forests in interior Alaska is particularly vulnerable, primarily due to the combustion of organic layer thickness in fire and the related increase in active layer thickness that exposes previously protected permafrost soil carbon to decomposition. This research was support from (1) the Department of Defense Strategic Environmental Research and Development Program (RC-2109), (2) the US Geological Survey and the Arctic, Western Alaska, and Northwest Boreal Landscape Conservation Cooperatives in Alaska through the Integrated Ecosystem Model for Alaska and Northwest Canada project, and (3) the National Science Foundation and the USDA Forest Service through the Bonanza Creek Long Term Ecological Research Program. Peer-reviewed Publisher Version |
format |
Article in Journal/Newspaper |
author |
Genet, H. McGuire, A. D. Barrett, Kirsten Breen, A. Euskirchen, E. S. Johnstone, J. F. Kasischke, E. S. Melvin, A. M. Bennett, A. Mack, M. C. |
spellingShingle |
Genet, H. McGuire, A. D. Barrett, Kirsten Breen, A. Euskirchen, E. S. Johnstone, J. F. Kasischke, E. S. Melvin, A. M. Bennett, A. Mack, M. C. Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska |
author_facet |
Genet, H. McGuire, A. D. Barrett, Kirsten Breen, A. Euskirchen, E. S. Johnstone, J. F. Kasischke, E. S. Melvin, A. M. Bennett, A. Mack, M. C. |
author_sort |
Genet, H. |
title |
Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska |
title_short |
Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska |
title_full |
Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska |
title_fullStr |
Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska |
title_full_unstemmed |
Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska |
title_sort |
modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior alaska |
publisher |
IOP Publishing |
publishDate |
2016 |
url |
http://iopscience.iop.org/article/10.1088/1748-9326/8/4/045016 http://hdl.handle.net/2381/37489 https://doi.org/10.1088/1748-9326/8/4/045016 |
long_lat |
ENVELOPE(-119.820,-119.820,55.917,55.917) |
geographic |
Arctic Canada Bonanza |
geographic_facet |
Arctic Canada Bonanza |
genre |
Active layer thickness Arctic permafrost Alaska |
genre_facet |
Active layer thickness Arctic permafrost Alaska |
op_relation |
Environmental Research Letters, 2013, 8 (4) http://iopscience.iop.org/article/10.1088/1748-9326/8/4/045016 http://hdl.handle.net/2381/37489 doi:10.1088/1748-9326/8/4/045016 1748-9326 |
op_rights |
Copyright © the authors, 2013. This is an open-access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/3.0/ ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1088/1748-9326/8/4/045016 |
container_title |
Environmental Research Letters |
container_volume |
8 |
container_issue |
4 |
container_start_page |
045016 |
_version_ |
1766328811452891136 |
spelling |
ftleicester:oai:lra.le.ac.uk:2381/37489 2023-05-15T13:03:07+02:00 Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska Genet, H. McGuire, A. D. Barrett, Kirsten Breen, A. Euskirchen, E. S. Johnstone, J. F. Kasischke, E. S. Melvin, A. M. Bennett, A. Mack, M. C. 2016-05-06T08:21:33Z http://iopscience.iop.org/article/10.1088/1748-9326/8/4/045016 http://hdl.handle.net/2381/37489 https://doi.org/10.1088/1748-9326/8/4/045016 en eng IOP Publishing Environmental Research Letters, 2013, 8 (4) http://iopscience.iop.org/article/10.1088/1748-9326/8/4/045016 http://hdl.handle.net/2381/37489 doi:10.1088/1748-9326/8/4/045016 1748-9326 Copyright © the authors, 2013. This is an open-access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/3.0/ ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY Journal Article Article 2016 ftleicester https://doi.org/10.1088/1748-9326/8/4/045016 2019-03-22T20:21:41Z There is a substantial amount of carbon stored in the permafrost soils of boreal forest ecosystems, where it is currently protected from decomposition. The surface organic horizons insulate the deeper soil from variations in atmospheric temperature. The removal of these insulating horizons through consumption by fire increases the vulnerability of permafrost to thaw, and the carbon stored in permafrost to decomposition. In this study we ask how warming and fire regime may influence spatial and temporal changes in active layer and carbon dynamics across a boreal forest landscape in interior Alaska. To address this question, we (1) developed and tested a predictive model of the effect of fire severity on soil organic horizons that depends on landscape-level conditions and (2) used this model to evaluate the long-term consequences of warming and changes in fire regime on active layer and soil carbon dynamics of black spruce forests across interior Alaska. The predictive model of fire severity, designed from the analysis of field observations, reproduces the effect of local topography (landform category, the slope angle and aspect and flow accumulation), weather conditions (drought index, soil moisture) and fire characteristics (day of year and size of the fire) on the reduction of the organic layer caused by fire. The integration of the fire severity model into an ecosystem process-based model allowed us to document the relative importance and interactions among local topography, fire regime and climate warming on active layer and soil carbon dynamics. Lowlands were more resistant to severe fires and climate warming, showing smaller increases in active layer thickness and soil carbon loss compared to drier flat uplands and slopes. In simulations that included the effects of both warming and fire at the regional scale, fire was primarily responsible for a reduction in organic layer thickness of 0.06 m on average by 2100 that led to an increase in active layer thickness of 1.1 m on average by 2100. The combination of warming and fire led to a simulated cumulative loss of 9.6 kgC m−2 on average by 2100. Our analysis suggests that ecosystem carbon storage in boreal forests in interior Alaska is particularly vulnerable, primarily due to the combustion of organic layer thickness in fire and the related increase in active layer thickness that exposes previously protected permafrost soil carbon to decomposition. This research was support from (1) the Department of Defense Strategic Environmental Research and Development Program (RC-2109), (2) the US Geological Survey and the Arctic, Western Alaska, and Northwest Boreal Landscape Conservation Cooperatives in Alaska through the Integrated Ecosystem Model for Alaska and Northwest Canada project, and (3) the National Science Foundation and the USDA Forest Service through the Bonanza Creek Long Term Ecological Research Program. Peer-reviewed Publisher Version Article in Journal/Newspaper Active layer thickness Arctic permafrost Alaska University of Leicester: Leicester Research Archive (LRA) Arctic Canada Bonanza ENVELOPE(-119.820,-119.820,55.917,55.917) Environmental Research Letters 8 4 045016 |