Forest Fires, Ecological Concerns
and Fire Suppression
The
United States Forest Service designates “critical biological areas,” which are
protected to a great extent against human impacts. These zones are
designed to conserve ‘species-at-risk;’ which are defined as being
‘specifically identified under the Endangered Species Act as threatened or
endangered, and/or by the NatureServe global conservation status ranking system
as being in jeopardy of extinction’ (Stein et al., 2010). Balancing
forest fire fuel reduction and fire prevention efforts, with the need to
conserve particular areas for the benefit of certain species is often a
difficult task. In this report I have considered sources with varying
viewpoints on critical biological areas; some arguing in support of critical
area species protection, as well as those which see this status as a hindrance
to fire management. As I will show, careful planning aided by the
powerful tool that is GIS can provide an effective route forward in combating,
and planning for forest fires.
The
United States government spends millions of dollars per year combating forest
fires across millions of hectares of forest. Active fire suppression
started in the United States around 1886. Soon after the creation of the
National Parks, the U.S. Army was tasked with patrolling the parks for fire
suppression surveillance purposes. Soon thereafter, serious discussions
took place wherein key figures such as the second U.S. Forest Service Chief
Henry Graves made a strong case for serious fire suppression policy.
Preemptive under burning to reduce fuel levels was encouraged; a policy he
believed was based on traditional Native American Indian fire techniques
(Stephens & Ruth, 2005). Clearing of fuel is a key method of forest
fire suppression and damage control. The idea is that by removing dead,
low-lying material from the forest floor, fires will spread less quickly, and
be easier for fire fighters to control. The Stephens and Ruth report
stresses the necessity of comprehensive forest fire management techniques, as
simply removing as much fuel as possible is not efficient. Factors such
as weather and topography play an important role in determining the best course
of fire prevention action, and can dictate whether or not removing fuel from
certain areas is efficient or even necessary. Managing a complex web of
data inputs and producing intuitive and coherent display of factor interaction
is a challenging task; one which can be nigh on impossible without the use of
GIS.
The
creation of fire danger maps using GIS software is instrumental in planning
regional forest fire management. GIS has the power to overlay many data
inputs in a single map projection; illuminating the interactions and
interdependence of many levels of fire suppression techniques. A 1996
article by Chuvieco & Salas appearing in the International Journal of
Geographical Information Science elaborates on the importance and utility of
GIS mapping in forest fire prevention, using a case study in Central
Spain. Chuvieco & Salas show how they used GIS mapping to create an
inclusive model of forest fire factors, and provided an in depth and
comprehensive report for the Spanish fire prevention service. Factors
such as climate play a large role in forest fire prevention. Most weather
monitoring is done in urban areas, at low elevations, which provides little to
no useful data for the concerned rural forest regions. Chuvieco &
Salas use interpolation of local climate data and prefabricated climate maps to
create relatively accurate weather data across large regions of forest.
This can be overlaid with data on topography, historical fires, soils,
vegetation, fire lookout towers, fire stations, fire roads, etc. The end
result was to create a GIS fire danger model for the region. The end
product ‘danger map’ included seven factors; “air temperature, humidity, slope,
aspect, fuel types, exposure of fuel types, and human fire risk,” (Chuvieco
& Salas 1996). The authors had to create their own digital elevation
model (DEM) of the region, which was done by digitizing from a 1:50,000 scale
map of the study area, and performing a linear interpolation to create the
elevation raster. GIS danger mapping is useful, but to create thoughtful
fire prevention policy, factors other than simple forest fire risk must be
considered. This is especially true in the case of controlled fuel burns,
in regards to their impact on local ecosystems.
Fires
effect local forest ecosystems greatly. Not only do fires dramatically
change the landscape, but the lack of fires due to vigilant
fire prevention can also have negative impacts on biodiversity and species
richness. In many regions, including the section of forest in Los Angeles
which was torched in the 2009 Station Fire, frequent small scale forest fires
are a natural part of the ecosystems. These fires cause the natural
succession and diversity of habitat necessary to maintaining a healthy
landscape. When humans artificially suppress wildfires, some species find
themselves with little to no habitat left, as they rely on new growth, and
without forest fires, thick undergrowth with tough subshrubs dominate the
landscape. While active forest fire prevention decreases the frequency of
forest fires, there may be a tendency for fires to be larger and more
devastating when they do happen. Without frequent fires, local flora and
fauna populations are prone to disastrous declines when fires do strike (Stein
et al., 2010). The implications of forest fires on species richness
become especially poignant in the case of critical biological areas.
These are areas which have been designated by the United States Forest Service
as containing at-risk species, and are afforded special protections
therefore. However, this can become a point of contention between
conservationists, and fire prevention advocates.
Controlled
burning of old growth forest fire fuel has for decades been the standard method
of fire prevention on forest lands. This becomes tricky when biologically
sensitive zones come into play. Some argue that without fire prevention
work in these areas, there will be an unacceptable risk of property damage due
to fire, and that the protected status of these lands is a hindrance to
productive fire prevention activities. T. L. Hanes 1971 work on
ecological succession in Southern California’s chaparral landscape sheds light
on the natural patterns and possible management techniques for fire prevention
in the region. Hanes observes that between the San Gabriel and San
Bernardino mountains, there are relatively few widespread or abundant plants.
He also finds that succession is slowest on the south facing slopes, desert and
oceanic exposure areas respond differently to post fire succession, etc.
A Los Angeles Times article, appearing on April 7, 2012 by Louis Sahgun
explores the efficacy of replanting forest lost in the 2009 Station Fire.
He finds that the planted trees have by in large died
off; out-competed by the natural succession of chaparral
plants. Attempts at restoring forest in a Mediterranean climate are yet
another attempt by humans at taming the landscape, and as we have seen, have
little to no positive effects. Natural succession patterns are vital for
supporting ecosystems, and anthropogenic fires, lack of fires, and forest
restoration are all ecologically deleterious. Observations such as those
described in Hanes’s work are crucial to creating intelligent and comprehensive
fire prevention policy. These factors can be included in a GIS model as
layers, and can direct fuel clearing or fire line creation in more efficient
and biologically sound directions.
Keeley,
Morais and Fotheringham’s 2002 work historic fire regime in Southern California
shrub lands provides an unbiased, and scientific view on fire prevention
work. They find that according to the California Statewide Fire History
Database, the intense fuel clearing efforts of the past decades has had little
to no effect on fire frequency or total area burned per year. Fire
intensity has not increased, and fire season has not changed since 1910.
They point to the high velocity winds of Southern California often will
overshadow the ability of fuel clearing at fire spread reduction. If you
look at the map I have created of the spread of the 2009 Station Fire, you will
see the distinct North and East progression of the fire; directly following
wind patterns in the area, regardless of fire suppression attempts.
The leading determinate in forest fire ignition and spread, is the ever
expanding “urban-wildland interface.” Keeley, Morais and Fotheringham
recommend focusing on strategic locations for fire prevention work, as opposed
to broad spectrum fuel clearing fire rotations across a widespread area.
They point to landscape features, and suggest creating defensible buffer zones
around at-risk areas. Later, in 2002, Keeley and Fotheringham published
another report on southern California fire regime. In this report, they
compare historic fire regimes in Southern California, and Northern Mexico, as
these two regions are historically similar, but in contemporary times,
California has undertaken massive fire prevention projects, while Mexico has
not. They find that there is actually little to no difference between the
regions, and that it is human encroachment on wild areas which has led to
increasing property damage, fire ignition and fire prevention expenditures.
My
research has led me to believe that preemptive fuel clearing is not a good
solution for fire prevention in the Station Fire area. Those who wish to
continue clearing fuel in the Station Fire area, irrespective of the critical
biological areas which are affected by such activities are misinformed.
They are relying on outdated information and practices. Instead, creation
of comprehensive GIS maps, which can guide fire prevention officials to find
defensible fire line locations, while avoiding disturbance of endangered
species is recommended. I have created a series of maps which illustrate
the parameters of the 2009 Station Fire, the elevations and topography of the
region, as well as critical biological areas in the region. With these
maps, fire prevention officials will be able to plan prevention projects around
endangered species, while concentrating their efforts and funds on more
strategic locations. [Maps located below reference list]
References
Chuvieco, E., & Salas, J.
(1996). Mapping the spatial distribution of forest fire danger using GIS.
International Journal of Geographical Information Science, 10(3), 333-345.
Hanes, T. L. (1971). Succession
after fire in the chaparral of southern California. Ecological monographs,
27-52.
Keeley, J. E.,
& Fotheringham, C. J. (2002). Historic fire regime in southern California
shrublands. Conservation Biology, 15(6), 1536-1548.
Keeley, J. E.,
Fotheringham, C. J., & Morais, M. (1999). Reexamining fire suppression
impacts on brushland fire regimes. Science, 284(5421), 1829-1832.
Sahagun, L. (2012, April 07).
Reforestation not taking hold in land burned by Station fire. The Los
Angeles Times. Retrieved March 17, 2013.
<http://articles.latimes.com/2012/apr/07/local/la-me-dead-trees-20120408>
Stein, S. M., Carr M. A., McRoberts,
R. E., Mahal, L. G., & Comas, S. J. (2010). Threats to At-Risk Species in
America’s Private Forests. USDA Forest Service Northern Research Station State
and Private Forestry: General Technical Report NRS-73.
Stephens, S. L.,
& Ruth, L. W. (2005). Federal forest-fire policy in the United States. Ecological
Applications, 15(2), 532-542.
Reference map for concerned Southern California area. |
Digital Elevation Model of concerned area. This can be used to determine fire spread around landscape features, and promising locations of fire lines and fuel clearing efforts. |
This map depicts the spread of the Station Fire. From 2:48 am on August 29th, to 12:39 am on September 2nd. Notice the South-North, and West-East spreading pattern of the fire. |
This map depicts the fire fighter stations near the Station Fire area. This is overlayed with a Digital Elevation Model, so as to facilitate easy fire management planning and strategizing. |