FIRE ECOLOGY 101 AGRONOMY NOTE NO. 355

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FIRE ECOLOGY 101

AGRONOMY NOTE NO. 355


by Linzy Browning


Although the 2002 fire season was relatively mild here in Montana, many states, including
Colorado, Arizona, and New Mexico, suffered a severe fire season. As humans, we tend to only
see fire as a

destructive force with the potential to threaten our property and lives. And it is!
However, fire also has an important ecological job. The following paragraphs give a brief
description of how fire naturally interacts with landscapes.


Interrelation of

Fire and Ecosystems

Because many ecosystems developed in the presence of fire, they adapted to it and came to rely
on it for natural cleaning and regeneration. Many grasses, shrubs, and tree seedlings see rapid
growth after a fire for several reasons. F
ire clears out old, dominant plants, creating a sudden
abundance of sunlight. The dark ash coating left by the fire retains more of this solar radiation,
and soil temperature often increases. Fire converts many of the nutrients stored in standing
plants
into readily usable forms and increases soil pH. These conditions are all conducive to
rapid growth of many different plant species following a fire.


Some species require fire for reproduction. Lodgepole and Jack pines have serotinous cones,
which mean
s they need heat in order to open and disperse their seeds. For some species, fire is a
requirement for seed germination, and for others it is simply an aid in reproduction and growth.


In any case, the complete suppression of fire in an ecosystem that de
veloped in its presence is an
unnatural disruption. Fuel loads increase beyond healthy levels, excessive amounts of nutrients
get tied up in vegetation, and just a few dominant plant species exist. When a fire finally occurs
in such an area, it burns wit
h greater intensity and has the potential to cause greater damage to
human establishments than fires that have less fuel to burn.


Wildlife and Fire

Although fire often destroys animal habitat, it actually creates new habitat very quickly.
Ecosystems that

naturally need fire actually support fewer wildlife species when they are
deprived of fire. Under such conditions, a few species dominate the landscape, and those species
are often not the most productive and nutritious species. After a fire, a wide var
iety of plant
species quickly flourish. The plants are very nutritious and support small and large species alike.




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Fire Management

Over 100 years ago, even before the creation of the U.S. Forest Service, the U.S. adopted the
policy of quickly suppressin
g all fires, regardless of the location or cause. This lead to years of
fuel buildup and declining health of both forests and rangeland. In the 1960's, this policy came
under scrutiny, and in subsequent years many fires were allowed to burn. Today, as i
n the past,
fire management is a tricky thing. Most people recognize the importance of fire, and controlled
burns have become a popular management practice. However, balancing ecological interests
with human interests and safety is a tough job and will p
robably only get tougher in the future.


Information in this article came from the following web sites:

http://www.riverdeep.net/current/2000/06/front.090600.fire.jhtml

http://psclasses.ucdavis.edu/POL
-
ARCH/esp166
-
2000
-
10
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faL/Docs&PDFs/Shaver2.rtf

http
://www.fire_ecology.org/education/doc1.htm

www.ets.uidaho.edu/range456/hot
-
topics/fire
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ecol.htm


Categories: Carbon, Soil Quality, Wildlife

Date: 2002