Agriculture Reference
In-Depth Information
CFL
is also important because it may be linked to many other important eco-
system attributes and canopy processes, such as productivity and light attenuation
(Keane et al.
2012b
). LAI is an important canopy characteristic in forest ecology be-
cause it determines rates of photosynthesis, shading, and precipitation interception
(rainfall that doesn't reach the ground) (Waring and Running
1998
), and it may be
highly related to
CFL
because
CFL
is mostly foliage (Keane et al.
2005
; Scott and
Reinhardt
2005
) (Table
4.1
). Like LAI,
CFL
is often correlated to common stand
measurements, such as basal area, tree density, and stand height (Alexander and
Cruz
2014
). The relationship of
CFL
to stand attributes may allow the indirect map-
ping of
CFL
using maps of stand variables (LAI, basal area) or using a statistical
model that relates
CFL
to the stand variables developed from field data (Chap. 9)
(Cruz et al.
2003
).
4.3.5
Canopy Cover
A last canopy fuel description variable that is needed outside of crown fire behav-
ior prediction but is often used in fire behavior modeling is
CC
, or the vertically
projected cover of the suspended canopy onto the ground. In many fire behavior
modeling systems, canopy cover is used to simulate fuel drying in forested stands
and, with
CH,
it is used to reduce midflame windspeeds (Finney
1998
). Canopy
cover is a canopy attribute that is used extensively in forestry and ecology, along
with its application in fire science. It is difficult to estimate
CC
in field settings with
any degree of accuracy or precision because of the wide diversity of canopy mate-
rial and the heterogeneous vertical profile of the canopy. Therefore, many estimate
CC
to the nearest 10 % using visual estimates or coarse measurement techniques
(Chap. 8). It has all the scale and measurement problems of
CBD, CH,
and
CBH
in
fire behavior and effects modeling.
References
Agee JK (1996) The influence of forest structure on fire behavior. In: Proceedings of the 17th an-
nual forest vegetation management conference, Redding. CA, USA, January 16-18, pp 52-68
Alexander ME (1988) Help with making crown fire hazard assessments. In: Fischer W, Arno SF
(eds) Protecting people and homes from wildfire in the interior West: proceedings of the sym-
posium and workshop. General Technical Report INT-251. USDA Forest Service, Intermoun-
tain Research Station, Ogden, pp 147-153
Alexander ME (1998) Crown fire thresholds in exotic pine plantations of Australasia. Ph.D. dis-
sertation, Australian National University. Canberra, Australia
Alexander ME, Cruz MG (2013) Are the applications of wildland fire behaviour models get-
ting ahead of their evaluation again? Environ Model Softw 41:65-71. doi:
http://dx.doi.
Alexander ME, Cruz MG (2014) Tables for estimating canopy fuel characteristics from stand
variables in four Interior West conifer forest types. Forest Science 60(4)784-794
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