Quantifying the flammability of living plants at the branch scale: which metrics to use?

J. G. Cawson; J. E. Burton; B. J. Pickering; V. Demetriou; A. I. Filkov

doi:10.1071/WF23007

RESEARCH ARTICLE (Open Access)

Previous Next Contents Vol 32(10)

Quantifying the flammability of living plants at the branch scale: which metrics to use?

J. G. Cawson

^A ^* , J. E. Burton

^A , B. J. Pickering ^A , V. Demetriou ^B and A. I. Filkov

^A

+ Author Affiliations

- Author Affiliations

^A FLARE Wildfire Research, Burnley, Vic. 3121, Australia.

^B Natural Hazards Research Australia, PO Box 116, Carlton South, Vic. 3053, Australia.

^* Correspondence to: jane.cawson@unimelb.edu.au

International Journal of Wildland Fire 32(10) 1404-1421 https://doi.org/10.1071/WF23007
Submitted: 18 January 2023 Accepted: 23 August 2023 Published: 15 September 2023

© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of IAWF. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Background

Plant flammability is an important factor in fire behaviour and post-fire ecological responses. There is consensus about the broad attributes (or axes) of flammability but little consistency in their measurement.

Aims

We sought to provide a pathway towards greater consistency in flammability research by identifying a subset of preferred flammability metrics for living plants.

Methods

Flammability was measured at the branch scale using a range of metrics for 140 plant specimens in an apparatus that simulates an approaching fire front.

Key results

We identified a subset of preferred metrics, which quantify the axes of flammability for living plants, including time to ignition (ignitability), peak heat release rate (combustibility), flaming duration (sustainability) and consumption (consumability). Flaming duration was strongly correlated with heat release rate, so could be a proxy for combustibility. Flammability was higher for species with greater surface area and biomass per branch.

Conclusions

We identified a subset of preferred metrics for quantifying the flammability of living plants. These metrics quantify the key axes of flammability and are measurable using different experimental apparatus and across multiple scales, making them suitable for widespread use.

Implications

The inclusion of these flammability metrics in future studies has the potential to enhance consistency and comparability between studies.

Keywords: branch scale, consumability, combustion, fire behaviour, fire intensity, flammability, fuel, ignition, quantifying flammability.

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