Reply to Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’

Our previous analysis of mapped records of forest fires in National Parks in Southwestern Australia showed that fires initiated a pulse in flammability (the likelihood of a point being burned by wildfire), but that flammability declined as forests matured (Zylstra et al 2022 Environ. Res. Lett.17 04...

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Main Authors: Zylstra, Philip, Lindenmayer, David B, Bradshaw, S Don
Format: Journal Article
Published: Institute of Physics (IoP) 2024
Online Access:http://hdl.handle.net/20.500.11937/95110
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author Zylstra, Philip
Lindenmayer, David B
Bradshaw, S Don
author_facet Zylstra, Philip
Lindenmayer, David B
Bradshaw, S Don
author_sort Zylstra, Philip
building Curtin Institutional Repository
collection Online Access
description Our previous analysis of mapped records of forest fires in National Parks in Southwestern Australia showed that fires initiated a pulse in flammability (the likelihood of a point being burned by wildfire), but that flammability declined as forests matured (Zylstra et al 2022 Environ. Res. Lett.17 044022). This reduction in flammability was contrary to that expected from modelling used by the West Australian Government to guide management, but consistent with expectations from peer-reviewed fire behaviour science and published ecological drivers of fire behaviour. Miller et al (2024 Environ. Res. Lett.) argued that our reported decline in flammability of long-unburnt forest is an artefact of poor data quality including flawed records kept by the West Australian Government, along with fewer and smaller sample sizes in long-unburnt forest. These problems, they claim, biased these age-classes toward values of zero flammability due to a rounding error. Critically, Miller et al (2024 Environ. Res. Lett.) did not test their hypothesis by repeating the analysis with these data removed. Here, we show that Miller et al's (2024 Environ. Res. Lett.) concerns are dependent upon the mathematical fallacy that rounding errors only occur in one direction (rounding flammability down to zero), when they have an equal likelihood of rounding upward and elevating flammability. The effect of this is to introduce noise rather than bias. We tested their hypothesis by repeating the analysis of Zylstra et al (2022 Environ. Res. Lett.17 044022) with a better suited statistical method on an improved and expanded dataset after removing the small patches that Miller et al (2024 Environ. Res. Lett.) proposed would bias the findings. Contrary to the objections of Miller et al (2024 Environ. Res.Lett.), removing lower quality data revealed that the mature forests were even less flammable than expected, so that only annual prescribed burning could reduce bushfire likelihood below that in forests unburnt for 56 years or more. Our findings highlight the role of prescribed burning in creating a more flammable landscape.
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spelling curtin-20.500.11937-951102024-06-18T00:39:30Z Reply to Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’ Zylstra, Philip Lindenmayer, David B Bradshaw, S Don Our previous analysis of mapped records of forest fires in National Parks in Southwestern Australia showed that fires initiated a pulse in flammability (the likelihood of a point being burned by wildfire), but that flammability declined as forests matured (Zylstra et al 2022 Environ. Res. Lett.17 044022). This reduction in flammability was contrary to that expected from modelling used by the West Australian Government to guide management, but consistent with expectations from peer-reviewed fire behaviour science and published ecological drivers of fire behaviour. Miller et al (2024 Environ. Res. Lett.) argued that our reported decline in flammability of long-unburnt forest is an artefact of poor data quality including flawed records kept by the West Australian Government, along with fewer and smaller sample sizes in long-unburnt forest. These problems, they claim, biased these age-classes toward values of zero flammability due to a rounding error. Critically, Miller et al (2024 Environ. Res. Lett.) did not test their hypothesis by repeating the analysis with these data removed. Here, we show that Miller et al's (2024 Environ. Res. Lett.) concerns are dependent upon the mathematical fallacy that rounding errors only occur in one direction (rounding flammability down to zero), when they have an equal likelihood of rounding upward and elevating flammability. The effect of this is to introduce noise rather than bias. We tested their hypothesis by repeating the analysis of Zylstra et al (2022 Environ. Res. Lett.17 044022) with a better suited statistical method on an improved and expanded dataset after removing the small patches that Miller et al (2024 Environ. Res. Lett.) proposed would bias the findings. Contrary to the objections of Miller et al (2024 Environ. Res.Lett.), removing lower quality data revealed that the mature forests were even less flammable than expected, so that only annual prescribed burning could reduce bushfire likelihood below that in forests unburnt for 56 years or more. Our findings highlight the role of prescribed burning in creating a more flammable landscape. 2024 Journal Article http://hdl.handle.net/20.500.11937/95110 10.1088/1748-9326/ad40c1 http://creativecommons.org/licenses/by/4.0/ Institute of Physics (IoP) fulltext
spellingShingle Zylstra, Philip
Lindenmayer, David B
Bradshaw, S Don
Reply to Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’
title Reply to Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’
title_full Reply to Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’
title_fullStr Reply to Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’
title_full_unstemmed Reply to Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’
title_short Reply to Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’
title_sort reply to comment on ‘self-thinning forest understoreys reduce wildfire risk, even in a warming climate’
url http://hdl.handle.net/20.500.11937/95110