The wildland fuel cell concept: an approach to characterize fine-scale variation in fuels and fire in frequently burned longleaf pine forests

Abstract

In ecosystems with frequent surface fire regimes, fire and fuel heterogeneity has been largely overlooked owing to the lack of unburned patches and the difficulty in measuring fire behavior at fine scales (0.1–10 m). The diverse vegetation in these ecosystems varies at these fine scales. This diversity could be driven by the influences of local interactions among patches of understorey vegetation and canopy-supplied fine fuels on fire behavior, yet no method we know of can capture fine-scale fuel and fire measurements such that these relationships could be rigorously tested. We present here an original method for inventorying of fine-scale fuels and in situ measures of fire intensity within longleaf pine forests of the south-eastern USA. Using ground-based LIDAR (Light Detection and Ranging) with traditional fuel inventory approaches, we characterized within-fuel bed variation into discrete patches, termed wildland fuel cells, which had distinct fuel composition, characteristics, and architecture that became spatially independent beyond 0.5 m2. Spatially explicit fire behavior was measured in situ through digital infrared thermography. We found that fire temperatures and residence times varied at similar scales to those observed for wildland fuel cells. The wildland fuels cell concept could seamlessly connect empirical studies with numerical models or cellular automata models of fire behavior, representing a promising means to better predict within-burn heterogeneity and fire effects.

Estimating Leaf Bulk Density Distribution in a Tree Canopy Using Terrestrial LiDAR and a Straightforward Calibration Procedure

“…Also, it does not provide a 3D biomass distribution. Calibration of TLS has also been used for fuel and fire effect characterization [25][26][27][28], but never in the past for leaf biomass estimation at plot scale.…”

Spatiotemporal Variability of Wildland Fuels in US Northern Rocky Mountain Forests

“…Reich et al [20] evaluated the spatial variability of several fuel components over a large landscape in the US Black Hills and found that the variability was governed by topography and vegetation. Hiers et al [21] measured small-scale variations in surface fuel using LiDAR and found that fuelbed depths become spatially independent after small distances (~0.5 m 2 ). Spatial variability of grasslands have been described in the context of population dynamics and restoration potential but have not been related to fuel characteristics [22].…”

Carbon Dynamics of Pinus palustris Ecosystems Following Drought

“…Strip head fires were then set perpendicular to the wind, starting on the downwind end of the unit and moving upwind. Fires were initiated 30-50 m apart depending on fuel patterns, local weather conditions, and fire behavior [33]. We limit our discussion of fire in this manuscript due to the short-duration, limited response these systems have shown to fire [20].…”