Introduction to Fire Ecology

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Transcript Introduction to Fire Ecology

Introduction to Fire Ecology
What is Fire?
Rapid oxidation
reaction in which
heat and light are
 Exothermic
 Three ingredients
Fire Factoids
Of known planets, only Earth has ingredients
essential for fire, oxygen, plant (for fuel), and
lightening to ignite the two into flames
90% of wildland fires started by humans,
most accidental.
10% by lightning, lava, heat of
~ 4.7 million acres burn annually United
Estimates suggest 100 million acres burned
annually before Europeans arrived
Fire Ecology
Branch of ecology
Focus on origins,
cycles, and effects of
wildland fire on
Wildland fire: any fire
burning in a natural
Fire ecologist tires to
relationships between
fire, living organisms
and their habitat.
Fire Ecology Concepts
Three main
concepts that
provide basis for
fire ecology
Fire history
Fire regime
Fire dependence/
Fire History
How often fire occurs in
a geographic area
 Trees and soil provide
evidence of past fires
 Fire scars seen in core
samples from trees
provide evidence of
past fires
 Ash layers in soil can
show fire patterns
 Intense fires can also
leave soil hydrophobic
Fire Regime
Patterns and cycles of
fire/ time
Severity: ecological
Intensity: fire behavior
Ex. High intensity- high
burn scars, crown fire,
but low severity- no soil
damage, undergrowth
Fire Dependence/ Adaptation
Concept applies to plants
and animals that rely on
fire or are adapted to
survive in fire prone
Plant adaptations
Serotinous cones, fire
resistant bark, heat resistant
foliage, rapid growth
Animal adaptations
Generally fleeing or
Communities Adapted to Fire
Six different vegetative
Tall Prarie (Midwest)
Ponderosa Pine (Interior
Douglas-Fir (Pacific
Loblolly and Shortleaf
Pine (The Southeast)
Jack Pine (Great Lake
Chaparral (California
and Southwest)
Tallgrass Prarie
Cover parts of Nebraska, Illinois, Iowa, and Kansas
Primarily grasses, forbs, shrubs, and trees
Fire helps maintain ecosystem stability and diversity
Benefits include elimination of invasive species
Ponderosa Pine
Location Eastern Oregon and Washington, West
Idaho, Extends into Interior West
Residing among Ponderosa pines include grasses
forbs, and shrubs
Generally receives less than 25 inches of rain a year
Fire serves to replace older plants with younger ones
of same species
Fire cycle of 5 to 25 years
Pacific Northwest,
Oregon, Washington,
Mixed forest with
climates that provide
over 50 inches of rain
Douglas-Fir regenerate
rapidly on site prepared
by fire
Benefits of fire include
removal of fuel and
consequent reduction
of severe crown fires
Loblolly and Shortleaf Pine
Southeast, Maryland,
Not highly adapted to
fire as in other species
Benefits of fire include
creation of favorable
environment for
seedlings and
hindrance of invasive
competing species
Jack Pine
Great Lakes States,
Michigan, Minnesota, etc.
 Found among a variety of
trees, brush, forbs, and grass
 Jack Pine do not drop all
their seeds
 Thick cone protects seeds on
trees during fire
 Seeds released where fire
removed existing vegetation
 Reduce competition
California and
 General term that
applies to various types
of brushland
 Many species are
adapted to and even
promote fire
 Fire releases nutrients
locked up in plants
 Reduces competition
by eliminating invasive