fire ecology notes ppt

Fire: Ecology, Behavior & Home

Agenda 11/2/16

• Wildfire Science– Definition of wildfire– Watch a couple of wildfire science videos– Fire Triangle– Fire Behavior Triangle– Learn about how fires spread

Fire is fire!

. . . Is it bad?

. . . Is it good?

. . . Who’s asking?

Fire is bad !

• Fire is good !

Ecological Effects of Fire Basic Premises

1. All ecosystems change over time2. Fire is neither innately good nor bad; it

is just an agent of change3. Human perception of whether it is good

or bad depends on resource objectives4. Do people think fire is good for wildlife?

WILDFIRE• Create a mental picture

• What does it look like?

• What does it sound like?

• What does it smell like?

• How would you define it?

Definition of Wildfire:

• An unplanned and uncontrolled fire spreading through vegetative fuels, at times involving structures.

Science of Wildfires• https://www.youtube.com/watch?v=F8OrmGAIqI4

Science of WildfireFIRE TRIANGLE

What is the source of :– Oxygen– Heat– Fuel

DEMO!

• Yep, time to examine the Fire Triangle.

Science of WildfireFIRE BEHAVIOR TRIANGLE– How does weather affect occurrence and spread of wildfire?– Which types of fuel feed a wildfire?– How can topography affect the occurrence and spread of wildfire?

Look at the factors• Weather

Look at the factors• Topography - Slope

Steep Slopes

Legend

Look at the factors• Fuel - Vegetation

Gap Data

Science of Wildfire- Types of Fuel

• Light Fuels• Heavy Fuels• Ladder Fuels• Fuel Breaks

Science of Wildfire• Fire Spread- Transference

of Heat– Conduction – Radiation => Surface fires– Convection => Crown fires

Fire Spread

Ember movement is the “wild card”

Ph

oto

Cr

ed

it:

Da

leW

ad

e,

US

DA

Fo

re

st

Se

rv

ice

Ph

oto

Cre

dit

:D

ale

Wa

de

,U

SD

AF

ore

stS

er

vic

e

High Intensity Crown Fire

https://www.youtube.com/watch?v=zvPa_yEEd4E

We have liftoff and ignition!

Agenda

• Update last set of notes (Fire spread)• History of fire policy in U.S. • Leading causes of fire in Oregon• Ecological Role of Fire

History of Fire in U.S.• 1800s- BIG forest fires began argument (among conservationists) that

fires threatened commercial timber supplies• 1891- U.S. Gov’t began setting aside national forest reservations• 1905- U.S. Forest Service established and given managerial control of

forest reservations• 1910- “Big Blowup”- 3 million acres burned in Montana, Idaho, and

Washington in only TWO days• “Big Blowup” greatly affected national conversation about fire policy

=> thought that total fire suppression would prevent big blowup again.

• 1920-1938- policies developed to – 1. Prevent Fires and – 2. Suppress fire as quickly as possible

• 1930s- Many fires led to even greater fire suppression urgency• 1944- Smokey Bear introduced to spread the message• 1960s- first scientific studies came out linking positive role fire played

in forest ecology• 1970s- Radical change in Forest Service policy

1970s Policy Changes

• Let fires burn when and where appropriate• Natural-caused fires allowed to burn in

designated wilderness areas• => “let-it-burn” policy • Last 25 years we’ve seen fires grown in size

and ferocity due to suppression efforts of early 1900s=> lots of money spent in effort to fight fires

History of Fire Suppression in 3 minutes

https://www.youtube.com/watch?v=NX1xnWPSjKg

Oregon Statistics

• 140,000 acres of Oregon burned in 2015• 595 people were responsible• Cost: $68,000,000• 297 fires were started at home• 55 fires started on the job

Oregon Statistics

Leading causes of fires in Oregon

• Cigarettes• Campfires build in poor locations• Campfires not properly extinguished• Fuel leakage from cars or logging equipment• Use of fireworks in any forestland area

What can YOU do to prevent wildfires?

What can you do to prevent starting a wildfire?

• Create defensible space around your home• Put out camp fires- there’s a science to this!• Build SMALL fires (not big bonfires) • If camping, use designated metal fire pits. • Don’t smoke. Anything. • No fireworks in public lands.

Ecological Role of Fire in Forest Ecosystems

1. Reduces probability of catastrophic fire

2. Nutrient input into soils3. Control of insect pests4. Control of tree pathogens5. Maintains species diversity

Fire Adaptations

1. Fire- activated seeds/cones2. Thermal insulation3. Resprouting4. Prolific Flowering5. Tall crowns and few to no

lower branches

Fire Activated Seeds• Require fire for seeds to sprout• Serotinous cones or fruit sealed with resin• Ex. Lodgepole Pine, Manzanita

Thermal Insulation

• Thick bark, dead leaves, or moist tissues prevents damage to inner layers of tree

Resprouting

• Grown new shoots after fire• Resprout from buds in plants underground• Ex. Madrone

Prolific Flowering

• Flowers pop up quickly after fires• Take advantage of ash-fertilized soil• Ex. Fire Lily

Tall Crown and Few Lower Branches

• Drop lower branches to prevent ladder fuels

• Called “self-pruning”• Ex. Ponderosa Pine

Healthy or Unhealthy?

BC

AB

Depends on Who You Ask!

Forester: “if its meeting management goals for that area and insect and disease were at” low levels.

Wildlife biologist: if it has a “mosaic of trees and openings providing a variety of habitat for a diversity of

wildlife.”

Hydrologist: “the most important component of a healthy forest is that there is ground cover…to act like a sponge, absorbing

water, filtering it and slowly releasing it.

Fire ecologist: “one that was disturbed by fire at a severity and frequency that mimicked what once

occurred naturally.”

Historically, fire would burn a stand every 40 years or less.

Wilderness specialist: “one where processes were allowed to play out without interference by humans.

Large bug kills are part of those processes…”

HEALTHY FORESTS?

UNHEALTHY FOREST??