Agriculture Reference
In-Depth Information
Although the prescription for the size of the fuel reduction buffer zone varies
with the site, generally 30 m is thought to provide adequate protection (Cohen
1999
), except on steep slopes where it may need to be much wider (Butler
2009
).
Some local and state governments mandate a 30-m or more
clearance zone
around
homes, but that term is misleading as clearing all vegetation is both unnecessary
and undesirable. There is evidence that reducing the volume of dead fuels and
thinning the density of live fuels is sufficient. Complete clearance not only
increases the chances of erosion but also has negative impacts on biodiversity
and aesthetics. In addition, complete clearance may lose some of the benefits of
vegetation; for example, there is anecdotal evidence that trees with moderate fuel
moisture may act as barriers to embers blowing into the urban environment.
Typically this buffer zone is created by modifying the natural vegetation
through mechanical clearing, prescription burning or other treatments. How-
ever, often this is impractical or extraordinarily expensive (Bradstock
et al.
1998b
). An alternative approach is that of creating a “green belt” in which
less flammable and irrigated vegetation is maintained within the buffer zone.
Sometimes this may be in the form of agricultural lands such as orchards or
grassy parklands or golf courses. However, creating such greenbelts requires co-
ordination of local and regional planning efforts, and in most regions this
problem remains unsolved.
Certainly one of the important determinants of factor
E
is due directly to land
planning decisions. “There are members in the community who believe that they
hold an inalienable right to live wherever, and however, they choose. It is not an
inescapable fact that whenever homes and lives are threatened by fire, there is a
community expectation that the firefighters will turn up and provide protection”
(Koperberg
2003
). Poor land-planning decisions put homes at risk, and road
infrastructure increases numbers and distribution of ignitions as well as increas-
ing access and effectiveness of fire suppression. Gill and Moore (
1997
) found
that fire incidence in jarrah forests of southwestern Australia had remained
constant over the past 40 yrs despite changes in roads, fire-fighting resources
and fuel management during that time. Syphard
et al.
(
2007
) found that fires
increase with increasing population density but as housing density increases and
the wildland-urban intermix changes to an interface situation fires drop. Water-
sheds of hazardous fuels need special zoning that restricts residential use, some-
thing that has long been noted by fire managers (e.g. Arnold
et al.
1951
;Leisz&
Wilson
1980
).
Certainly part of the solution to reducing community vulnerability is more
strategic land planning that considers avoidance of high fire hazard areas.
Numerous factors will likely need to be considered in altering planning deci-
sions (Moritz & Stephens
2008
). Land zoning based on fire history is
one obvious means of effecting change (Bovio & Camia
1997
). While this
is important for the future there are huge legacies of risk due to past planning
decisions and the desire to rebuild and remain undefeated by nature following
disastrous fires.
