The behavior of live fuels during wildfire has been a contentious topic in the scientific community for several decades. Until recently, live fuels were often modeled as if they were moist dead fuels, despite growing evidence to the contrary. Recent research has revealed significant differences between the burning behavior of live and dead fuels, including the fact that live fuels can sustain and spread flames at much higher moisture levels and with popping and snapping sounds. While statistical studies have examined the correlation between various parameters and the moisture content of live and dead fuels, a fundamental understanding of live fuel ignition and spread has remained elusive. At IR4TD, we have made significant strides in live fuel fire research by utilizing a hybrid infrared-schlieren visualization and scaling analysis technique [1]. Our findings suggest that live fuels exhibit micro-explosive behaviors that heat adjacent fuels through intermittent flame impingements, allowing fire to spread in a discrete model. This discovery is crucial for wildfire modeling, as it explains why live fuels can sustain flames even under high moisture content and gust conditions when compared to dead fuels. Furthermore, this research will inform the selection of live fuel surrogates for use in fire spread studies, enabling more accurate predictions of real-world fire behavior. For more information, please contact us. References1. Darwish Ahmad, A., et al., Ignition and burning mechanisms of live spruce needles. Fuel, 2021. 304: p. 121371.