THE EXTREME PROJECT STUDIES THE RELEASE OF FLAMMABLE VOLATILES DURING PRESCRIBED FIRES IN THE ALBANY PINE BUSH PRESERVE
The full explanation of the extreme fire behaviour observed in some wildfires should include the effect of high local concentrations of flammable volatiles released by leaves exposed to high temperatures and/or by products of incomplete combustion. In specific conditions of fuel, topography, and wind, those flammable volatiles can mix with air, reach their flammability limits and ignite with very high intensity creating explosive situations.
Thus, in order to understand the specific conditions on which the volatiles release can contribute to these extreme events, the EXTREME project has been performing field studies and laboratory experiments with leaves of Pinus pinaster Aiton, Eucalyptus globulus Labill., Quercus suber L. and Quercus robur L., collected in Sintra, and has been analysing satellite data from Portuguese wildfires.
To consolidate the studies conducted in Portugal, and in order to scale up with field tests of experimental fires, the EXTREME team contacted Neil Gifford (Conservation Director at Albany Pine Bush Preserve Commission) and found the prescribed fire program with the Albany Pine Bush Preserve, in Northeastern America, close to the KASSAY Company that furnishes the necessary equipment for the tests. This opportunity was ideal to perform these studies, since the Albany Pine Bush Preserve program includes the use of prescribed fire for maintaining an open ecosystem of sand dunes with Pinus rigida Mill, and thus allowing for the maintenance of the wild blue lupine (Lupinus perennis L.), a host of the endangered Karner blue butterfly (Plebejus melissa samuelis Edwards).
Members of the project team, Francisco Castro Rego, Leónia Nunes, Cátia Magro and Oriana Gonçalves, together with fire managers of Albany Pine Bush Preserve, Tyler Briggs, Todd Compani and David Brickner, worked together from May 14 to May 29, 2022. With the support of Stephen Perry and Rob Crampton, from KASSAY, the team used specialized open path Fourier-transform infrared (FTIR) spectrometer, able to scan a full range of volatiles released by the vegetation during a fire.
During the first week, the research team trained with the open path FTIR equipment performing pre-fire measurements, as well as experimental burning tests with branches and needles of Pinus strobus L. and P. rigida. The second week was dedicated to the measurements during prescribed fires in four different management units of the Albany Pine Bush Preserve: Dromedary, Dorsum, Cupcake and Asphalt. The fires burned in different fuel types, topography and wind creating a diversity of situations that enrich the interest of the results.
The prescribed fires were all extremely well managed with great expertize, organization, and logistics. The full support from the fire management team allowed data acquisition to be fully completed, with great efficiency.
From the team’s preliminary analysis, the data indicates that volatile compounds as products of incomplete combustion, carbon monoxide and methane as expected, are present in smoke in significant amounts. Additionally, and as one of the ultimate goals of the project, the volatiles released as the monoterpenes α-pinene, β-pinene and limonene, released by the leaves, were also detected in fire’s smoke.
Furthermore, subsequent data analyses and a modelling approach will allow the integration of the different components of the EXTREME project from the chemistry to the landscape level. A decision support system will use the information gathered.
Funding and support:
The work has received funding from the Foundation for Science and Technology (FCT) under the EXTREME project “Influence of VOCs (volatile organic compounds) on the extreme behavior of forest fires”, with the reference PCIF/GFC/0078/2018
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EXTREME project
Tuesday, 14 June 2022
