Fuel Classifications - Wildland Fuel Fundamentals and Applications - page 111

associative approach (e.g., combine a classification of stand structure with a cover
type classification). The addition of new classifications or classes exponentially
increases the amount of fuel data needed to cover all combinations of the merged
classifications; so many combinations might be missing valuable fuel data to
quantify fuel information.

7.2.2 Opportunistic

In the opportunistic approach to fuel classification, unique fuelbeds are subjectively
identified in the field and selected as a new category to include in the classifica-
tion based on their representativeness for a region, vegetation type, or fuel type.
The newly identified fuelbed becomes a new class in the classification once the
fuel component properties are measured and assigned to this fuelbed. Keane ( 2013 )
called this a “bottom-up” indirect classification approach where there are an infinite
number of classes possible in this ever-expanding classification method.
Two fuel classifications provide excellent examples of this opportunistic
approach: the photo series (Chap. 8) and the Fuel Characteristics Classification
System (FCCS). In both, new and unique fuelbeds can be added as they are identified
by managers, scientists, and resources specialists in the field for local, regional, or
national applications (Berg 2007 ). When new fuelbeds are sampled, the resultant
data become attributes of the new class in the classification (Riccardi et al. 2007b ).
The photo series is a set of photographs of fuelbeds where fuel component loadings
have been measured (Fig. 7.1 ). These photographs are usually described and strati-
fied by vegetation characteristics, such as cover type or species composition. Each
photo in the series becomes a category in the classification and many have used
photo series photos to describe and quantify fuel characteristics (Keyes 2002 ). The
FCCS is a more formal adoption of an opportunistically derived fuel classification
(Ottmar et al. 2007 ). In the FCCS, unique fuelbeds are identified, either in the field
or office, and then directly or indirectly sampled to populate a database that links

Fig. 7.1 A picture from the
Fischer (1980) photo series