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INTRODUCTION / INTRODUCTION
Characterizing and classifying complex fuels — A
new approach
Erik Berg
In the United States, fire managers have relied on a small
number of stylized fuel models for over 30 years (Anderson
1982) — standard descriptions of homogeneous surface fuel
constituents associated with specific types of fire
behaviour — as inputs to mathematical calculations of surface fire behaviour. Other systems for describing fuels and
calculating fire behaviour have been developed for Canada
(Forestry Canada Fire Danger Group 1992) and Australia
(Cheney and Sullivan 1997). Scientists and managers are
seeking more accurate predictions of fire behaviour and
fire effects for operational use, planning, and simulations.
While categorical descriptors of fuels have served managers reasonably well in the past, improved predictions might
require more comprehensive descriptions of fuelbeds (soil
organic matter and all live and dead vegetation) that discriminate among fuel components.
Regional resource managers challenged scientists at the
US Forest Service Pacific Wildland Fire Sciences Laboratory to develop a comprehensive library of measured fuelbeds that would meet their needs for quantifying fuels over
a wide range of vegetative types, such as temperate rainforests, dry ponderosa pine (Pinus ponderosa Dougl. ex P. &
C. Laws.) forests, juniper (Juniperus spp.) woodlands, and
sagebrush (Artemisia spp.). In principle, realistic multistrata
fuelbeds could better represent fuels than could stylized
models, providing information about the biophysical environment that would be useful to assessment of fire and biological conditions.
The Fuel Characteristic Classification System (FCCS) was
developed in response to this challenge. A significant component of the FCCS is a large fuelbed library complied
from federal agencies and the scientific literature. This data
library assembled from ecosystems throughout the United
States includes quantitative and qualitative variables for a
wide range of structural components.
The FCCS could potentially provide input for a variety of
applications including fire behaviour, fire effects on ecological components (e.g., standing dead wood and large woody
debris), smoke production (e.g., calculation of particulate
Received 8 August 2007. Accepted 8 August 2007. Published on
the NRC Research Press Web site at cjfr.nrc.ca on 14 December
2007.
E. Berg. US Geological Survey, 12201 Sunrise Valley Drive,
Mail Stop 301, Reston, VA 20192, USA (e-mail:
eberg@usgs.gov).
Can. J. For. Res. 37: 2381–2382 (2007)
emissions), and stand dynamics modeling (e.g., stem density
and stem sizes). For example, the FCCS fuelbeds are already
being used as inputs for calculating fuel consumption and
large-scale emissions (Wiedinmyer et al. 2006).
The articles in this feature describe and document the key
components and applications of the FCCS. Because the
FCCS is a substantial departure from traditional fuel inventory and modeling concepts, extensive input has been elicited from scientists and resource managers in North
America during development and beta testing. In addition,
the FCCS was formally reviewed by a panel of 12 fire scientists in November 2005. Scientists asked important questions about the validity and scientific foundation of the
FCCS. For example, could measured fuelbeds better account
for differences in fire behaviour and effects than could stylized fuel models? The following articles were revised in response to this extensive review prior to submission for
publication and additional peer review.
The article by Ottmar et al. (2007) provides an overview
of the history and derivation of the FCCS. Riccardi et al.
(2007a, 2007b) provide detail of the FCCS, individual fuels
strata, inventory procedures, and calculation of fuel properties. Sandberg et al. (2007b) presents a fresh conceptual approach to fire behaviour modeling based on a reformulation
of the Rothermel (1972) model. Sandberg et al. (2007a) discusses the conceptual basis and calculation of fire potentials.
Schaaf et al. (2007) builds on Sandberg et al. (2007b) in the
development of a new conceptual approach to crown fire potential. Finally, McKenzie et al. (2007) demonstrate how
FCCS fuelbeds have been mapped at large spatial scale
across forested landscapes.
References
Anderson, H.E. 1982. Aids to determining fuel models for estimating fire behavior. USDA For. Serv. Gen. Tech. Rep. INT-122.
Brown, J.K. 1971. A planar intersect method for sampling fuel volume and surface area. For. Sci. 17: 96–102.
Cheney, P., and Sullivan, A. 1997. Grassfires: fuel, weather and
fire behaviour. Commonwealth Scientific and Industrial Research Organisation, Collingwood, Australia.
Forestry Canada Fire Danger Group. 1992. Development and structure of the Canadian forest fire behaviour prediction system.
Can. For. Serv. Ottawa, Ont. Inf. Rep. ST-X-3. p. 3.
McKenzie, D., Raymond, C.L., Kellogg, L.-K., Norheim, R., Andreu, A., Bayard, A., Kopper, K., and Elman, E. 2007. Mapping
doi:10.1139/X07-150
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fuels at multiple scales: landscape application of the Fuel Characteristic Classification System. Can. J. For. Res. 37. This issue.
Ottmar, R.D., Sandberg, D.V., Riccardi, C.L., and Prichard, S.J.
2007. An overview of the Fuel Characteristic Classification
System — Quantifying, classifying, and creating fuelbeds for resource planners. Can. J. For. Res. 37. This issue.
Riccardi, C.L., Ottmar, R.D., Sandberg, D.V., Andreu, A.G., Elman, E., Kopper, K., and Long, J. 2007a. The fuelbed: a key
element of the Fuel Characteristic Classification System. Can. J.
For. Res. 37. This issue.
Riccardi, C.L., Prichard, S.J., Sandberg, D.V., and Ottmar, R.D.
2007b. Quantifying physical characteristics of wildland fuels in
the Fuel Characteristic Classification System. Can. J. For. Res.
37. This issue.
Rothermel, R.C. 1972. A mathematical model for predicting fire
spread in wildland fuels. USDA For. Serv. Res. Pap. INT-115.
Can. J. For. Res. Vol. 37, 2007
Sandberg, D.V., Riccardi, C.L., and Schaaf, M.D. 2007a. Fire potential rating for wildland fuelbeds using the Fuel Characteristic
Classification System. Can. J. For. Res. 37. This issue.
Sandberg, D.V., Riccardi, C.L., and Schaaf, M.D. 2007b. Reformulation of Rothermel’s wildland fire behaviour model for heterogeneous fuelbeds. Can. J. For. Res. 37. This issue.
Schaaf, M.D., Sandberg, D.V., and Riccardi, C.L. 2007. A conceptual model of crown fire potential using the reformulated wildland fire behaviour model. Can. J. For. Res. 37. This issue.
Wiedinmyer, C., Quayle, B., Geron, C., Belote, A., McKenzie, D.,
Zhang, X., O’Neill, S., and Wynne, K.K. 2006. Estimating emissions from fires in North America for air quality modeling. Atmos. Environ. 40: 3419–3432. doi:10.1016/j.atmosenv.2006.02.
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