Spatial and seasonal flammability comparisons of native and exotic plants in the Post Oak Savannah, Blackland Prairie, and Pineywoods Ecoregions of TexasThis article is part of a larger document. View the larger document here.
Greater knowledge of plant flammability can improve prescribed fire effectiveness and wildfire mitigation strategies by improving fire behavior predictions in physics-based fire models and supplementing Firewise plant listings with flammability indices. Seasonal and regional changes in flammability parameters were estimated for yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), greenbrier (Smilax spp.), and Chinese tallow (Triadica sebifera) within the Post Oak Savannah, Blackland Prairie, and Pineywoods Ecoregions of Texas. Foliage (yaupon, privet, and greenbriar) and wood (tallow) samples were collected in the dormant (February) and growing (August) seasons. Wood samples were collected from Chinese tallow due to dormant season leaf-off. Samples were evaluated using thermogravimetric analysis to estimate relative spontaneous ignition temperature (RSIT) and gas-phase maximum mass loss rate (GP-MMLR). RSIT and GP-MMLR are estimates of plant ignitability and combustibility. Yaupon was the most ignitable species during both seasons and across all three ecoregions. Chinese privet dormant season ignitability was similar to yaupon in the Post Oak Savannah and Blackland Prairie. Greenbrier exhibited the greatest growing season combustibility combined with moderate ignitability. Chinese tallow wood exhibited substantially greater ignitability and combustibility in the growing season. Collectively, all species exhibited seasonal and ecoregion variances in ignitability, while combustibility varied little relative to season and ecoregion. These data provide insight into potential species-specific contributions to fire behavior that may aid in more informed fire management planning.