Relation of Silica Content to Flammability in Grasses

Abstract

Two highly combustible western grasses, cheatgrass ( Bromus tectorum L.) and medusahead ( Taeniatherum asperum (Sim.) Nevski) differ greatly in total ash content. Ash contents of cheatgrass and medusahead are 5.04 and 18.49 percent, respectively, but silica-free ash contents are 0.99 and 1.35 percent. Thermoanalyses indicated pyrolytic similarity between the two grasses. Results suggest that the silica fraction should be discounted when relating ash content to pyrolysis and ignition processes of wildland fuels. Forest Sci. 16:64-65.