Get reliable rangeland science

Prescribed fire managers are encountering difficulties with the increase of cool-season non-native species in warm-season grasslands. Rothermel�s fire spread equation treats all herbaceous fuels as a single fine fuel class, a valid assumption under extremely dry conditions for which the original fuel models were developed. Increased interest in growing season burns and altered plant community composition from invasive species introduces a novel degree of variability to the fine fuel component of grassland fuel beds, but differences in the flammability of various grass species is poorly understood. Flammability, a concept linked to how plant material burns, is measured inconsistently with multiple response variables reported (e.g. mass loss rate, % biomass consumed, rate of heat release, burning duration). Thus, there is no common framework for flammability in grasslands, which limits scalability to fire behavior at a landscape level. We ignited dried biomass of native and non-native grass species common to the Great Plains in the fume hood to produce two curves, (1) mass loss over time, recorded by a four-point balance and logged every 0.2 s, and (2) change in temperature over time, using a thermocouple datalogger with multiple sensors placed at various positions in and above the plant material. These curves and their slopes will assist in identifying differences in fuel in terms of components of flammability. Characterizing differences in fuel properties, such as flammability, provides insight into species-specific influences. These species-specific data can be scaled up to a landscape level by anticipating differences in fire behavior based on a relative abundance of species in the fuel bed.