Recent massive expansion of wildfire and its impact on active layer over pan-Arctic permafrost
Wildfire is recognized as an increasing threat to the southern boreal forests and the permafrost beneath them, with less occurring over the cold continuous permafrost than before. However, we show that continuous permafrost was a major contribution to wildfire expansion in the pan-Arctic over the la...
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Format: | Article |
Language: | English |
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IOP Publishing
2023-01-01
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Series: | Environmental Research Letters |
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Online Access: | https://doi.org/10.1088/1748-9326/ace205 |
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author | Xingru Zhu Xiyan Xu Gensuo Jia |
author_facet | Xingru Zhu Xiyan Xu Gensuo Jia |
author_sort | Xingru Zhu |
collection | DOAJ |
description | Wildfire is recognized as an increasing threat to the southern boreal forests and the permafrost beneath them, with less occurring over the cold continuous permafrost than before. However, we show that continuous permafrost was a major contribution to wildfire expansion in the pan-Arctic over the last two decades. The expansion rate of burned area over continuous permafrost was 0.9 Mha decade ^−1 , in contrast to a decreasing trend (−0.5 Mha decade ^−1 ) over the entire permafrost areas. Burned area has been rapidly growing in the north of the Arctic Circle in particular, where the total burned area in the major fire seasons during 2011–2020 nearly doubled that during 2001–2010. Wildfire expansion is closely linked to an increased soil moisture deficit, considering wildfires there combust more than 90% of belowground fuel. Continuous permafrost experiences more severe fire-induced degradation. Active layer thickening following wildfires over continuous permafrost lasts more than three decades to reach a maximum of more than triple the pre-fire thickness. These new findings highlight the massive expansion of wildfires over continuous permafrost, which can dramatically modify ecological processes, disturb organic carbon stock, and thus accelerate the positive feedback between permafrost degradation and climate warming. |
first_indexed | 2024-03-12T15:49:17Z |
format | Article |
id | doaj.art-c24610b523bd4f87935bd79d38b1317c |
institution | Directory Open Access Journal |
issn | 1748-9326 |
language | English |
last_indexed | 2024-03-12T15:49:17Z |
publishDate | 2023-01-01 |
publisher | IOP Publishing |
record_format | Article |
series | Environmental Research Letters |
spelling | doaj.art-c24610b523bd4f87935bd79d38b1317c2023-08-09T15:18:06ZengIOP PublishingEnvironmental Research Letters1748-93262023-01-0118808401010.1088/1748-9326/ace205Recent massive expansion of wildfire and its impact on active layer over pan-Arctic permafrostXingru Zhu0https://orcid.org/0000-0002-5005-1610Xiyan Xu1https://orcid.org/0000-0003-2732-1325Gensuo Jia2https://orcid.org/0000-0001-5950-9555Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, People’s Republic of China; University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaKey Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, People’s Republic of ChinaKey Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, People’s Republic of China; University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaWildfire is recognized as an increasing threat to the southern boreal forests and the permafrost beneath them, with less occurring over the cold continuous permafrost than before. However, we show that continuous permafrost was a major contribution to wildfire expansion in the pan-Arctic over the last two decades. The expansion rate of burned area over continuous permafrost was 0.9 Mha decade ^−1 , in contrast to a decreasing trend (−0.5 Mha decade ^−1 ) over the entire permafrost areas. Burned area has been rapidly growing in the north of the Arctic Circle in particular, where the total burned area in the major fire seasons during 2011–2020 nearly doubled that during 2001–2010. Wildfire expansion is closely linked to an increased soil moisture deficit, considering wildfires there combust more than 90% of belowground fuel. Continuous permafrost experiences more severe fire-induced degradation. Active layer thickening following wildfires over continuous permafrost lasts more than three decades to reach a maximum of more than triple the pre-fire thickness. These new findings highlight the massive expansion of wildfires over continuous permafrost, which can dramatically modify ecological processes, disturb organic carbon stock, and thus accelerate the positive feedback between permafrost degradation and climate warming.https://doi.org/10.1088/1748-9326/ace205active layer thicknessbelowground combustionpermafrostwildfire |
spellingShingle | Xingru Zhu Xiyan Xu Gensuo Jia Recent massive expansion of wildfire and its impact on active layer over pan-Arctic permafrost Environmental Research Letters active layer thickness belowground combustion permafrost wildfire |
title | Recent massive expansion of wildfire and its impact on active layer over pan-Arctic permafrost |
title_full | Recent massive expansion of wildfire and its impact on active layer over pan-Arctic permafrost |
title_fullStr | Recent massive expansion of wildfire and its impact on active layer over pan-Arctic permafrost |
title_full_unstemmed | Recent massive expansion of wildfire and its impact on active layer over pan-Arctic permafrost |
title_short | Recent massive expansion of wildfire and its impact on active layer over pan-Arctic permafrost |
title_sort | recent massive expansion of wildfire and its impact on active layer over pan arctic permafrost |
topic | active layer thickness belowground combustion permafrost wildfire |
url | https://doi.org/10.1088/1748-9326/ace205 |
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