No Cover Image

Journal article 316 views 111 downloads

Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk

Alastair J Crawford, Claire M Belcher, James I L Morison, Stefan Doerr Orcid Logo, Nicholas Kettridge, Gareth D Clay

Forestry: An International Journal of Forest Research, Start page: cpaf029

Swansea University Author: Stefan Doerr Orcid Logo

  • 69650.VOR.pdf

    PDF | Version of Record

    © The Author(s) 2025. Published by Oxford University Press on behalf of Institute of Chartered Foresters. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (CC BY).

    Download (2.28MB)

Check full text

DOI (Published version): 10.1093/forestry/cpaf029

Abstract

The UK faces increased wildfire risk due to climate change, but efforts to improve forecasting of this risk are limited by a lack of data on fuel properties. We assessed tree leaf litter flammability and ground fuel (litter and duff) moisture in samples from six managed forest plantations across Gre...

Full description

Published in: Forestry: An International Journal of Forest Research
ISSN: 0015-752X 1464-3626
Published: Oxford University Press (OUP) 2025
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa69650
first_indexed 2025-06-09T10:35:42Z
last_indexed 2025-10-18T09:46:19Z
id cronfa69650
recordtype SURis
fullrecord <?xml version="1.0"?><rfc1807><datestamp>2025-10-17T10:03:46.9947584</datestamp><bib-version>v2</bib-version><id>69650</id><entry>2025-06-09</entry><title>Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk</title><swanseaauthors><author><sid>575eb5094f2328249328b3e43deb5088</sid><ORCID>0000-0002-8700-9002</ORCID><firstname>Stefan</firstname><surname>Doerr</surname><name>Stefan Doerr</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2025-06-09</date><deptcode>BGPS</deptcode><abstract>The UK faces increased wildfire risk due to climate change, but efforts to improve forecasting of this risk are limited by a lack of data on fuel properties. We assessed tree leaf litter flammability and ground fuel (litter and duff) moisture in samples from six managed forest plantations across Great Britain over the course of one year. We sampled litter and duff monthly, from Scots &amp;amp; Corsican pine [Pinus sylvestris L. and Pinus nigra subsp. laricio (Poir.) Maire], Sitka &amp;amp; Norway spruce [Picea sitchensis (Bong.) Carri&#xE8;re and Picea abies (L.) H.Karst.], and Silver birch (Betula pendula Roth) plantations (representative of long-needled, short-needled, and broadleaved trees), measured moisture content, and used cone calorimetry to obtain data on leaf litter flammability. We examined relationships between rainfall, litter moisture, and flammability, and showed that cumulative rainfall over the previous 20&#x2013;25 days most strongly influenced litter moisture, which in turn accounted for much of the variation in flammability. Silver birch maintained higher litter moisture than coniferous species throughout the year, which may be attributed to differences in leaf morphology, decomposition and phenology between broadleaves and conifers. All species reached minima of both litter moisture and duff moisture low enough to sustain burning during the year. While previous studies have often used artificially composed litter samples to demonstrate the effects of leaf properties (especially leaf shape) on flammability, our results using unmodified litter only partially confirm these effects. Interspecies differences in the peak heat release rate may be attributable to both structural properties and volatile content of the litter. However, differences in total heat release, previously attributed to leaf morphology, were evident only when measured on an areal basis, and not on a mass basis. Our data do not support the hypothesis that the morphology of broadleaves results in more ignitable litter beds. This study presents forest litter flammability data through an annual cycle for the first time, and the first extensive litter flammability data from the British Isles. It provides fuel moisture and heat content data that will contribute to the development of fuel models for UK forest environments, enabling forest management that is better informed about fire risk.</abstract><type>Journal Article</type><journal>Forestry: An International Journal of Forest Research</journal><volume>0</volume><journalNumber/><paginationStart>cpaf029</paginationStart><paginationEnd/><publisher>Oxford University Press (OUP)</publisher><placeOfPublication/><isbnPrint/><isbnElectronic/><issnPrint>0015-752X</issnPrint><issnElectronic>1464-3626</issnElectronic><keywords>flammability; cone calorimetry; forest fire; forest fuels; forest litter; heat release</keywords><publishedDay>30</publishedDay><publishedMonth>5</publishedMonth><publishedYear>2025</publishedYear><publishedDate>2025-05-30</publishedDate><doi>10.1093/forestry/cpaf029</doi><url/><notes/><college>COLLEGE NANME</college><department>Biosciences Geography and Physics School</department><CollegeCode>COLLEGE CODE</CollegeCode><DepartmentCode>BGPS</DepartmentCode><institution>Swansea University</institution><apcterm>Another institution paid the OA fee</apcterm><funders>This work was part of the NERC-funded &#x2018;Towards a UK Fire Danger Rating System&#x2019; project (reference NE/T003553/1).</funders><projectreference/><lastEdited>2025-10-17T10:03:46.9947584</lastEdited><Created>2025-06-09T11:29:50.6634222</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Biosciences, Geography and Physics - Geography</level></path><authors><author><firstname>Alastair J</firstname><surname>Crawford</surname><order>1</order></author><author><firstname>Claire M</firstname><surname>Belcher</surname><order>2</order></author><author><firstname>James I L</firstname><surname>Morison</surname><order>3</order></author><author><firstname>Stefan</firstname><surname>Doerr</surname><orcid>0000-0002-8700-9002</orcid><order>4</order></author><author><firstname>Nicholas</firstname><surname>Kettridge</surname><order>5</order></author><author><firstname>Gareth D</firstname><surname>Clay</surname><order>6</order></author></authors><documents><document><filename>69650__34421__0346afe44cc44e2ca7224b5ee60098f7.pdf</filename><originalFilename>69650.VOR.pdf</originalFilename><uploaded>2025-06-09T11:33:38.5469614</uploaded><type>Output</type><contentLength>2392212</contentLength><contentType>application/pdf</contentType><version>Version of Record</version><cronfaStatus>true</cronfaStatus><documentNotes>&#xA9; The Author(s) 2025. Published by Oxford University Press on behalf of Institute of Chartered Foresters. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (CC BY).</documentNotes><copyrightCorrect>true</copyrightCorrect><language>eng</language><licence>https://creativecommons.org/licenses/by/4.0/</licence></document></documents><OutputDurs/></rfc1807>
spelling 2025-10-17T10:03:46.9947584 v2 69650 2025-06-09 Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk 575eb5094f2328249328b3e43deb5088 0000-0002-8700-9002 Stefan Doerr Stefan Doerr true false 2025-06-09 BGPS The UK faces increased wildfire risk due to climate change, but efforts to improve forecasting of this risk are limited by a lack of data on fuel properties. We assessed tree leaf litter flammability and ground fuel (litter and duff) moisture in samples from six managed forest plantations across Great Britain over the course of one year. We sampled litter and duff monthly, from Scots &amp; Corsican pine [Pinus sylvestris L. and Pinus nigra subsp. laricio (Poir.) Maire], Sitka &amp; Norway spruce [Picea sitchensis (Bong.) Carrière and Picea abies (L.) H.Karst.], and Silver birch (Betula pendula Roth) plantations (representative of long-needled, short-needled, and broadleaved trees), measured moisture content, and used cone calorimetry to obtain data on leaf litter flammability. We examined relationships between rainfall, litter moisture, and flammability, and showed that cumulative rainfall over the previous 20–25 days most strongly influenced litter moisture, which in turn accounted for much of the variation in flammability. Silver birch maintained higher litter moisture than coniferous species throughout the year, which may be attributed to differences in leaf morphology, decomposition and phenology between broadleaves and conifers. All species reached minima of both litter moisture and duff moisture low enough to sustain burning during the year. While previous studies have often used artificially composed litter samples to demonstrate the effects of leaf properties (especially leaf shape) on flammability, our results using unmodified litter only partially confirm these effects. Interspecies differences in the peak heat release rate may be attributable to both structural properties and volatile content of the litter. However, differences in total heat release, previously attributed to leaf morphology, were evident only when measured on an areal basis, and not on a mass basis. Our data do not support the hypothesis that the morphology of broadleaves results in more ignitable litter beds. This study presents forest litter flammability data through an annual cycle for the first time, and the first extensive litter flammability data from the British Isles. It provides fuel moisture and heat content data that will contribute to the development of fuel models for UK forest environments, enabling forest management that is better informed about fire risk. Journal Article Forestry: An International Journal of Forest Research 0 cpaf029 Oxford University Press (OUP) 0015-752X 1464-3626 flammability; cone calorimetry; forest fire; forest fuels; forest litter; heat release 30 5 2025 2025-05-30 10.1093/forestry/cpaf029 COLLEGE NANME Biosciences Geography and Physics School COLLEGE CODE BGPS Swansea University Another institution paid the OA fee This work was part of the NERC-funded ‘Towards a UK Fire Danger Rating System’ project (reference NE/T003553/1). 2025-10-17T10:03:46.9947584 2025-06-09T11:29:50.6634222 Faculty of Science and Engineering School of Biosciences, Geography and Physics - Geography Alastair J Crawford 1 Claire M Belcher 2 James I L Morison 3 Stefan Doerr 0000-0002-8700-9002 4 Nicholas Kettridge 5 Gareth D Clay 6 69650__34421__0346afe44cc44e2ca7224b5ee60098f7.pdf 69650.VOR.pdf 2025-06-09T11:33:38.5469614 Output 2392212 application/pdf Version of Record true © The Author(s) 2025. Published by Oxford University Press on behalf of Institute of Chartered Foresters. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (CC BY). true eng https://creativecommons.org/licenses/by/4.0/
title Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk
spellingShingle Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk
Stefan Doerr
title_short Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk
title_full Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk
title_fullStr Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk
title_full_unstemmed Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk
title_sort Fuel moisture and flammability of leaf litter in British forest plantations and their implications for wildfire risk
author_id_str_mv 575eb5094f2328249328b3e43deb5088
author_id_fullname_str_mv 575eb5094f2328249328b3e43deb5088_***_Stefan Doerr
author Stefan Doerr
author2 Alastair J Crawford
Claire M Belcher
James I L Morison
Stefan Doerr
Nicholas Kettridge
Gareth D Clay
format Journal article
container_title Forestry: An International Journal of Forest Research
container_volume 0
container_start_page cpaf029
publishDate 2025
institution Swansea University
issn 0015-752X
1464-3626
doi_str_mv 10.1093/forestry/cpaf029
publisher Oxford University Press (OUP)
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Biosciences, Geography and Physics - Geography{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Biosciences, Geography and Physics - Geography
document_store_str 1
active_str 0
description The UK faces increased wildfire risk due to climate change, but efforts to improve forecasting of this risk are limited by a lack of data on fuel properties. We assessed tree leaf litter flammability and ground fuel (litter and duff) moisture in samples from six managed forest plantations across Great Britain over the course of one year. We sampled litter and duff monthly, from Scots &amp; Corsican pine [Pinus sylvestris L. and Pinus nigra subsp. laricio (Poir.) Maire], Sitka &amp; Norway spruce [Picea sitchensis (Bong.) Carrière and Picea abies (L.) H.Karst.], and Silver birch (Betula pendula Roth) plantations (representative of long-needled, short-needled, and broadleaved trees), measured moisture content, and used cone calorimetry to obtain data on leaf litter flammability. We examined relationships between rainfall, litter moisture, and flammability, and showed that cumulative rainfall over the previous 20–25 days most strongly influenced litter moisture, which in turn accounted for much of the variation in flammability. Silver birch maintained higher litter moisture than coniferous species throughout the year, which may be attributed to differences in leaf morphology, decomposition and phenology between broadleaves and conifers. All species reached minima of both litter moisture and duff moisture low enough to sustain burning during the year. While previous studies have often used artificially composed litter samples to demonstrate the effects of leaf properties (especially leaf shape) on flammability, our results using unmodified litter only partially confirm these effects. Interspecies differences in the peak heat release rate may be attributable to both structural properties and volatile content of the litter. However, differences in total heat release, previously attributed to leaf morphology, were evident only when measured on an areal basis, and not on a mass basis. Our data do not support the hypothesis that the morphology of broadleaves results in more ignitable litter beds. This study presents forest litter flammability data through an annual cycle for the first time, and the first extensive litter flammability data from the British Isles. It provides fuel moisture and heat content data that will contribute to the development of fuel models for UK forest environments, enabling forest management that is better informed about fire risk.
published_date 2025-05-30T12:30:23Z
_version_ 1850852636761260032
score 11.08895

Similar Items