Introduction - Wildland Fuel Fundamentals and Applications - page 10

a fuel classification key that integrated fire behavior categories with vegetation and
structural characteristics. Matthews ( 1937 ) even developed a plot-based sampling
method to sample these fire behavior categories to describe fuel at finer scales.
These fuel classification and mapping efforts had many problems, mostly because
they described fire behavior not fuels. Brown and Davis ( 1973 ) recognized several
other reasons why fuel descriptions based on fire behavior were ineffective: (1)
expensive (costly to train and implement), (2) lack of detail (too broad to be applied
locally), (3) obsolescence (mapped fuel types rapidly changed over a short time),
(4) narrowly focused (evaluated for worst case burning conditions and envisioned
the area burning in only large fires), (5) limited application (could not be used for
other fire management tasks), and most importantly, (6) no associated comprehen-
sive technique for measuring fuels.
Another historical approach often used for assessing fuels involved naming and
describing fuelbeds based on vegetation characteristics. Mitchell ( 1929 ), for exam-
ple, described the unique fuels of the mid-western USA using vegetation types. Fuel
types in New Jersey, USA, were named after forest vegetation types for fire danger
prediction (Little 1945 ). The basis of the Show and Kotok ( 1930 ) fuel descriptions
was broadly defined vegetation types. Barrows ( 1951 ) stratified fire occurrence sta-
tistics by two vegetation-based fuel types (timber and grass), three management
activity types (cutover, burned, forested), and several forest types in his description
of wildfires in the US northern Rocky Mountains. Wendel et al. ( 1962 ) sampled
fuel weights for various vegetation types in southeastern USA and then used the
fuel weights to assign potential fire behavior ratings. Fuel classification systems
for Ontario and New Brunswick, Canada, were based on vegetation characteristics
(Walker 1971 ).
Both of these historical approaches ignored the inherent complexity of a fuelbed
and attempted to simplify fuelbed descriptions into something that could be eas-
ily understood by managers. It was much easier to relate a fuelbed to a recogniz-
able vegetation type or to some abstract interpretation of fire behavior than directly
quantify the diverse array of fuel types in a fuelbed. The main reason for this was
simple; there really wasn't any reason to stratify the fuelbed into its components.
It wasn't until analytical tools, methods, and models were developed for fire man-
agement that there became a reason for dissecting fuelbeds into components and
describing component properties.
The prediction of fire danger was the first concerted effort at creating a fire man-
agement tool (Hardy and Hardy 2007 ). Gisborne ( 1936 ), for example, differentiated
fuel types in the fuelbed to more accurately estimate fuel moisture to predict fire
danger and Curry and Fons ( 1938 ) differentiated fuel types to predict fire spread for
fire danger. Fahnestock ( 1970 ) developed one of the first comprehensive fuel as-
sessment methods that described the fuelbed as a complex of integrated fuel types.
He used various fuel type properties, such as size, shape, and continuity, of three
different fuel layers (ground, surface, crown) to rate the potential for spread and
crowning. In the 1960s and 1970s, fire scientists around the world started creating
fire behavior models that were then implemented into a variety of fire behavior
prediction systems for managers. These systems required users to input specific