Age of rough
n. Time since last fire in a southern rough fuelbed.
Age of rough is a significant determinant of potential fire behavior in southern rough. Southern rough regrows very quickly after fire, so the fuel load changes significantly with each year after a fire. In general, southern rough areas are usually available to burn six months to one year after a fire, and a reburn within this period usually has mild fire effects. On the other hand, after two to three years, fire can be severe in high fire danger conditions. Southern rough over the age of five years may be considered to be a hazardous fuel situation under any burnable condition.
Vegetation height may be used as a surrogate for age of rough. Tables exist to approximate fuel loads for various ages or heights of rough (see McNab and Edwards 1976 and Hough and Albini 1978).