NIST - National Institute of Standards and Technology

06/29/2026 | Press release | Archived content

The Burning Character of 3 m to 7 m Douglas-Fir Trees with Varying Moisture Content

Published
June 29, 2026

Author(s)

Giovanni Di Cristina Torres, Erik Johnsson, Eric Mueller, Matthew Bundy, Anthony Chakalis, Marco Fernandez, Artur Chernovsky, Aika Davis, Anthony Hamins

Abstract

A series of experiments is reported on the burning behavior of 3.3 m to 7.4 m tall, Douglas-fir trees with the dry basis moisture content varying from 7 % to 55 %. The results quantified the transient, peak, and total heat release rates (HRR) as well as the mass loss, the yields of carbon monoxide, particulate matter, and PAH, and the near and far-field heat fluxes. Photogrammetry documented the initial and final tree geometry and characterized the crown volume, while cameras recorded multiple perspectives of the fire's evolution. The fires exhibited rapid growth, reaching peak HRRs within 7 s to 18 s after ignition with vertical flame spread as fast as 2 m/s. Higher moisture content was found to significantly decrease both the radiative fraction and the particulate matter yield. The total heat release measured by oxygen consumption calorimetry and the ideal heat release from mass loss were in reasonable agreement. Post-fire analysis revealed thicker branch tip diameters as smaller fuel elements were consumed. The results provide unique calorimetric data useful for development of design fire scenarios and fire research and are available on the NIST Fire Calorimetry Database (FCD).
Citation
Technical Note (NIST TN) - 2362
Report Number
2362
NIST Pub Series
Pub Type
NIST Pubs

Keywords

burning rate, Douglas-fir trees, fire calorimetry database, heat release rate, radiative emission, WUI fires

Citation

Di Cristina Torres, G. , Johnsson, E. , Mueller, E. , Bundy, M. , Chakalis, A. , Fernandez, M. , Chernovsky, A. , Davis, A. and Hamins, A. (2026), The Burning Character of 3 m to 7 m Douglas-Fir Trees with Varying Moisture Content, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.TN.2362, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=961036 (Accessed July 2, 2026)
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NIST - National Institute of Standards and Technology published this content on June 29, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on July 03, 2026 at 03:48 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]