Fire Regime GROUPS
USFWS uses the national, coarse-scale classification of five fire regime groups based on frequency and severity:
I. Frequent (0-35 years), low-severity
II. Frequent (0-35 years), stand replacement severity
III. 35-100+ years, mixed severity
IV. 35-100+ years, stand replacement severity
V. 200+ years, stand replacement severity
Map credit: USDA Fire Sciences Laboratory, Rocky Mountain Research Station.