Device for the standard measurement of shoot flammability in the field

JAUREGUIBERRY, P.; BERTONE, G.; DÍAZ, S.

AUSTRAL ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Canberra; Año: 2011 vol. 36 p. 821 - 829

1442-9985

Fire ecology has been hindered by the lack of comparable, affordable protocols to quantify theflammability of whole plants over large numbers of species.We describe a low-tech device that can be carried to thefield and that allows highly standardized measurement of the flammability of whole individuals or portions up to70 cm long.We illustrate its potential with results for 34 species belonging to different growth forms from centralArgentina. The device consists of an 85 ¥ 60 cm half-cut metallic barrel placed horizontally and mounted on aremovable metallic structure. It contains three parallel burners, a grill with an attached gauging thermometer anda blowtorch. Burners and blowtorch are connected to a propane?butane gas cylinder. Plant samples are placed onthe grill and preheated with the burners for 2 min at 150°C.They are then ignited for 10 s with the blowtorch whilethe burners are kept on. Four parameters are measured for each sample: maximum temperature reached, burningtime, burnt length and burnt biomass percentage.These parameters are used to construct a compound index offlammability for each sample that ranges between 0 (no flammability) and around 3 (maximum flammability).Weobtained a wide range of values for flammability and all its components.Most of this variability was accounted forby differences between growth forms and species, rather than by differences at the level of replicates.This suggeststhat the device and protocol are sensitive enough to detect flammability differences among plants with differentfunctional traits, and at the same time robust enough to produce consistent results among samples with similartraits. A major advantage is that plant architecture is kept almost intact, providing a flammability measure muchcloser to that of whole individuals in the field than those obtained by other standard protocols in use.The deviceand protocol presented here should facilitate the acquisition of comparable flammability data over large numbersof species from different floras and ecosystems, potentially contributing to several fields of research, such asfunctional ecology, evolutionary ecology and vegetation-atmosphere modelling.