Impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone
Wildfire frequency and extent is increasing throughout the boreal forest-tundra ecotone as climate warms. Understanding the impacts of wildfire throughout this ecotone is required to make predictions of the rate and magnitude of changes in boreal-tundra landcover, its future flammability, and associ...
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ftdoajarticles:oai:doaj.org/article:8370d46a07a848ad93f0a17e6931cb6f 2023-05-15T13:09:48+02:00 Impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone Xanthe J. Walker Brain K. Howard Mélanie Jean Jill F. Johnstone Carl Roland Brendan M. Rogers Edward A. G. Schuur Kylen K. Solvik Michelle C. Mack 2021-01-01T00:00:00Z https://doaj.org/article/8370d46a07a848ad93f0a17e6931cb6f EN eng Public Library of Science (PLoS) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8553150/?tool=EBI https://doaj.org/toc/1932-6203 1932-6203 https://doaj.org/article/8370d46a07a848ad93f0a17e6931cb6f PLoS ONE, Vol 16, Iss 10 (2021) Medicine R Science Q article 2021 ftdoajarticles 2022-12-31T05:23:25Z Wildfire frequency and extent is increasing throughout the boreal forest-tundra ecotone as climate warms. Understanding the impacts of wildfire throughout this ecotone is required to make predictions of the rate and magnitude of changes in boreal-tundra landcover, its future flammability, and associated feedbacks to the global carbon (C) cycle and climate. We studied 48 sites spanning a gradient from tundra to low-density spruce stands that were burned in an extensive 2013 wildfire on the north slope of the Alaska Range in Denali National Park and Preserve, central Alaska. We assessed wildfire severity and C emissions, and determined the impacts of severity on understory vegetation composition, conifer tree recruitment, and active layer thickness (ALT). We also assessed conifer seed rain and used a seeding experiment to determine factors controlling post-fire tree regeneration. We found that an average of 2.18 ± 1.13 Kg C m-2 was emitted from this fire, almost 95% of which came from burning of the organic soil. On average, burn depth of the organic soil was 10.6 ± 4.5 cm and both burn depth and total C combusted increased with pre-fire conifer density. Sites with higher pre-fire conifer density were also located at warmer and drier landscape positions and associated with increased ALT post-fire, greater changes in pre- and post-fire understory vegetation communities, and higher post-fire boreal tree recruitment. Our seed rain observations and seeding experiment indicate that the recruitment potential of conifer trees is limited by seed availability in this forest-tundra ecotone. We conclude that the expected climate-induced forest infilling (i.e. increased density) at the forest-tundra ecotone could increase fire severity, but this infilling is unlikely to occur without increases in the availability of viable seed. Article in Journal/Newspaper alaska range north slope Tundra Alaska Directory of Open Access Journals: DOAJ Articles |
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Directory of Open Access Journals: DOAJ Articles |
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English |
topic |
Medicine R Science Q |
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Medicine R Science Q Xanthe J. Walker Brain K. Howard Mélanie Jean Jill F. Johnstone Carl Roland Brendan M. Rogers Edward A. G. Schuur Kylen K. Solvik Michelle C. Mack Impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone |
topic_facet |
Medicine R Science Q |
description |
Wildfire frequency and extent is increasing throughout the boreal forest-tundra ecotone as climate warms. Understanding the impacts of wildfire throughout this ecotone is required to make predictions of the rate and magnitude of changes in boreal-tundra landcover, its future flammability, and associated feedbacks to the global carbon (C) cycle and climate. We studied 48 sites spanning a gradient from tundra to low-density spruce stands that were burned in an extensive 2013 wildfire on the north slope of the Alaska Range in Denali National Park and Preserve, central Alaska. We assessed wildfire severity and C emissions, and determined the impacts of severity on understory vegetation composition, conifer tree recruitment, and active layer thickness (ALT). We also assessed conifer seed rain and used a seeding experiment to determine factors controlling post-fire tree regeneration. We found that an average of 2.18 ± 1.13 Kg C m-2 was emitted from this fire, almost 95% of which came from burning of the organic soil. On average, burn depth of the organic soil was 10.6 ± 4.5 cm and both burn depth and total C combusted increased with pre-fire conifer density. Sites with higher pre-fire conifer density were also located at warmer and drier landscape positions and associated with increased ALT post-fire, greater changes in pre- and post-fire understory vegetation communities, and higher post-fire boreal tree recruitment. Our seed rain observations and seeding experiment indicate that the recruitment potential of conifer trees is limited by seed availability in this forest-tundra ecotone. We conclude that the expected climate-induced forest infilling (i.e. increased density) at the forest-tundra ecotone could increase fire severity, but this infilling is unlikely to occur without increases in the availability of viable seed. |
format |
Article in Journal/Newspaper |
author |
Xanthe J. Walker Brain K. Howard Mélanie Jean Jill F. Johnstone Carl Roland Brendan M. Rogers Edward A. G. Schuur Kylen K. Solvik Michelle C. Mack |
author_facet |
Xanthe J. Walker Brain K. Howard Mélanie Jean Jill F. Johnstone Carl Roland Brendan M. Rogers Edward A. G. Schuur Kylen K. Solvik Michelle C. Mack |
author_sort |
Xanthe J. Walker |
title |
Impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone |
title_short |
Impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone |
title_full |
Impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone |
title_fullStr |
Impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone |
title_full_unstemmed |
Impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone |
title_sort |
impacts of pre-fire conifer density and wildfire severity on ecosystem structure and function at the forest-tundra ecotone |
publisher |
Public Library of Science (PLoS) |
publishDate |
2021 |
url |
https://doaj.org/article/8370d46a07a848ad93f0a17e6931cb6f |
genre |
alaska range north slope Tundra Alaska |
genre_facet |
alaska range north slope Tundra Alaska |
op_source |
PLoS ONE, Vol 16, Iss 10 (2021) |
op_relation |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8553150/?tool=EBI https://doaj.org/toc/1932-6203 1932-6203 https://doaj.org/article/8370d46a07a848ad93f0a17e6931cb6f |
_version_ |
1766199746045673472 |