Grass Fuel Models

Grass fuel models range from very fine porous fuels to continuous herbaceous fuels that are cured or nearly cured. Grasses have high surface area to volume ratios, can lose or gain moisture quickly, and expose much of the combustible tissue to the air. Consequently, grass fires spread rapidly but burn out quickly (Anderson 1982). Wind strongly affects fire and the most extreme rates of spread can be as high as 30% of the wind speed.

Grass is found in most ecosystems, but is the dominant and most influential fuel in arid and range lands. Southern ecosystems with dominant grass fuels are open longleaf pine forests, dry prairie, the Everglades, and pastures. When surveying an area to determine fuel model, the percentage of grass should exceed 66%.

Grass fuel models make up FPBS models 1-3.