Table 4 National Park Service form FMH-21 was used to standardize burn severity. Values were reversed for this study with heavily burned as 5 and unburned as 1

Substrate

Not burned

Litter partially blackened; duff nearly unchanged; wood/leaf structures unchanged

Litter charred to partially consumed; upper duff layer may be charred but the duff layer is not altered over the entire depth; surface appears black; woody debris is partially burned; logs are scored or blackened but not charred; rotten wood is scorched to partially burned

Litter mostly to entirely consumed, leaving coarse, light colored ash; duff deeply charred, but underlying mineral soil is not visibly altered; woody debris is mostly consumed; logs are deeply charred, burned-out stump holes are common

Litter and duff completely consumed, leaving fine white ash; mineral soil visibly altered, often reddish; sound logs are deeply charred, and rotten logs are completely consumed. This code generally applies to less than 10% of natural or slash burned areas

Vegetation

Not burned

Foliage scorched and attached to supporting twigs

Foliage and smaller twigs partially to completely consumed; branches mostly intact

Foliage, twigs, and small stems consumed; some branches still present

All plant parts consumed, leaving some or no major stems/trunks; any left are deeply charred