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...

Full description

Bibliographic Details
Main Authors: Xingru Zhu, Xiyan Xu, Gensuo Jia
Format: Article
Language:English
Published: IOP Publishing 2023-01-01
Series:Environmental Research Letters
Subjects:
Online Access:https://doi.org/10.1088/1748-9326/ace205
_version_ 1797747334378946560
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
work_keys_str_mv AT xingruzhu recentmassiveexpansionofwildfireanditsimpactonactivelayeroverpanarcticpermafrost
AT xiyanxu recentmassiveexpansionofwildfireanditsimpactonactivelayeroverpanarcticpermafrost
AT gensuojia recentmassiveexpansionofwildfireanditsimpactonactivelayeroverpanarcticpermafrost