Flame interactions and burning characteristics of two live leaf samples

Abstract

Combustion experiments were performed over a flat-flame burner that provided the heat source for multiple leaf samples. Interactions of the combustion behavior between two leaf samples were studied. Two leaves were placed in the path of the flat-flame burner, with the top leaf 2.5 cm above the bottom leaf. Local gas and particle temperatures, as well as local oxygen concentrations, were measured along with burning characteristics of both leaves. Results showed that the time to ignition of the upper leaf was not significantly affected by the presence of the lower leaf. The major difference observed was that the time of flame duration of the upper leaf was significantly affected by the presence of the lower leaf. Causes for the prolonged flame were found to be the consumption of oxygen by the burning lower leaf and the obstruction provided by the lower leaf, causing a wake effect, thus altering the combustion behavior of the upper leaf.

Landscape variation in plant leaf flammability is driven by leaf traits responding to environmental gradients

“…Our study focused on leaf flammability, and while this is only one of several important components contributing to fire behavior in fire‐prone systems, it is a critical component given that leaves are frequently the first structures to ignite during bushfire (Gill and Moore , Pickett et al. ) and will likely dictate much of the behavior of fire spread through vegetation (Zylstra et al. ).…”

“…Leaves are frequently the first structures to ignite during bushfire (Pickett et al. ), promulgating fire to other plant structures and fuel sources. Furthermore, leaves contribute a large proportion of the living biomass available to a fire and recent modeling has shown that the properties of living fuel, in particular plant leaves, are an important factor in landscape fire (Zylstra et al.…”

Effects of vegetation type and fire regime on flammability of undisturbed litter in Southeastern France

“…For instance, among the most frequent parameters studied, we found in literature: (i) the fuel moisture content or bulk density (Plucinski and Anderson, 2008;Dimitrakopoulos et al, 2006), (ii) the vegetation type (Fonda, 2001;Fonda et al, 1998;Fonda and Varner, 2004;Kane et al, 2008;Ganteaume et al, 2009a) or (iii) the terpene content (Ormeño et al, 2009). Flammability experiments were also performed over a flat-flame burner that provided the heat source for multiple leaf samples, simulating an oncoming flame front (Pickett et al, 2009). At another level, using Mutch's methods (1970), Taylor and Fonda (1990) assessed flammability characteristics of fuel, burning reasonably intact litter samples that mixed some woody fuels with largely non-woody fuels.…”

Pyro-Ecophysiology: Shifting the Paradigm of Live Wildland Fuel Research

“…Plant canopies must be sufficiently dense to ensure that fire can spread efficiently between foliage and canopies closer to the ground may be more easily ignited by a passing surface fire [21]. Foliar flame durations can be influenced by the arrangement of foliage in a canopy and the interactions between multiple particles [22]. Further, in canopies with mixtures of live and dead branches, canopy architecture can have a strong influence on fire temperatures and heat release [23].…”