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APPENDIX D

b. The overstory is not decadent; there is only a FUEL MODEL D
nominal accumulation of debris. This fuel model is specifically for the palmetto-gallberry
(1) The needles are 2 inches (51 mm) or more in understory-pine overstory association of the southeast
length (most pines). coastal plains. It can also be used for the so-called “low
pocosins” where Fuel Model O might be too severe. This
(a) Eastern United States: MODEL P
model should only be used in the Southeast, because of a
(b) Western United States: MODEL U high moisture of extinction.
(2) The needles are less than 2 inches (51 mm) FUEL MODEL E
long: MODEL H
Use this model after leaf fall for hardwood and mixed
VI.Slash is the predominant fuel. hardwood-conifer types where the hardwoods dominate.
A. The foliage is still attached; there has been little set- The fuel is primarily hardwood leaf litter. The oat-hickory
tling. types are best represented by Fuel Model E, but E is an
1. The loading is 25 tons/acre (56.1 tons/ha) or acceptable choice for northern hardwoods and mixed for-
greater: MODEL I ests of the Southeast. In high winds, the fire danger may
be underrated because rolling and blowing leaves are not
2. The loading is less than 25 tons/acre (56.1 tons/ha) accounted for. In the summer after the trees have leafed
but more than 15 tons/acre (33.7 tons/ha): MODEL out, Fuel Model E should be replaced by Fuel Model R.
J
FUEL MODEL F
3. The loading is less than 15 tons/acre (33.7 tons/ha):
MODEL K Fuel Model F is the only one of the 1972 NFDR System
Fuel Models whose application has changed. Model F now
B. Settling is evident; the foliage is falling off; grasses, represents mature closed chamise stands and oakbrush
forbs, and shrubs are invading the area.
fields of Arizona, Utah and Colorado. It also applies to
1. The loading is 25 tons/acre (56.1 tons/ha) or young, closed stands and mature, open stands of California
greater: MODEL J mixed chaparral. Open stands of pinyon-juniper are repre-
2. The loading is less than 25 tons/acre (56.1 tons/ha): sented; however, fire activity will be overrated at low
MODEL K wind speeds and where there is sparse ground fuels.
FUEL MODEL A FUEL MODEL G
This fuel model represents western grasslands vegetated Fuel Model G is used for dense conifer stands where there
by annual grasses and forbs. Brush or trees may be present is a heavy accumulation of litter and downed woody mate-
but are very sparse, occupying less than a third of the area. rial. Such stands are typically overmature and may also be
Examples of types where Fuel Model A should be used are suffering insect, disease, wind or ice damage-natural
cheatgrass and medusahead. Open pinyon-juniper, sage- events that create a very heavy buildup of dead material on
brush-grass, and desert shrub associations may appropri- the forest floor. The duff and litter are deep, and much of
ately be assigned this fuel model if the woody plants meet the woody material is more than 3 inches (76 mm) in
the density criteria. The quantity and continuity of the diameter. The undergrowth is variable, but shrubs are usu-
ground fuels vary greatly with rainfall from year to year. ally restricted to openings. Types meant to be represented
by Fuel Model G are hemlock-Sitka spruce, Coast Doug-
FUEL MODEL B
las-fir, and wind-thrown or bug-killed stands of lodgepole
Mature, dense fields of brush 6 feet (1829 mm) or more in pine and spruce.
height are represented by this fuel model. One-fourth or FUEL MODEL H
more of the aerial fuel in such stands is dead. Foliage
burns readily. Model B fuels are potentially very danger- The short-needled conifers (white pines, spruces, larches
ous, fostering intense, fast-spreading fires. This model is and firs) are represented by Fuel Model H. In contrast to
for California mixed chaparral generally 30 years or older. Model G fuels, Fuel Model H describes a healthy stand
The F model is more appropriate for pure chamise stands. with sparse undergrowth and a thin layer of ground fuels.
The B model may also be used for the New Jersey pine Fires in H fuels are typically slow spreading and are dan-
barrens. gerous only in scattered areas where the downed woody
material is concentrated.
FUEL MODEL C
FUEL MODEL I
Open pine stands typify Model C fuels. Perennial grasses
and forbs are the primary ground fuel but there is enough Fuel Model I was designed for clearcut conifer slash
needle litter and branchwood present to contribute signifi- where the total loading of materials less than 6 inches (152
cantly to the fuel loading. Some brush and shrubs may be mm) in diameter exceeds 25 tons/acre (56.1 metric tons/
present but they are of little consequence. Situations cov- ha). After settling and the fines (needles and twigs) fall
ered by Fuel Model C are open, longleaf, slash, ponderosa, from the branches, Fuel Model I will overrate the fire
Jeffrey, and sugar pine stands. Some pinyon-juniper stands potential. For lighter loadings of clearcut conifer slash, use
may qualify. Fuel Model J, and for light thinnings and partial cuts

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38 2015 INTERNATIONAL WILDLAND-URBAN INTERFACE CODE
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