Climate Change

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Climate Change FireWhat Might We Expect?

• Carl N. Skinner
• Project Leader
• USFS Pacific Southwest Research Station
• Redding, CA

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Climate Change?
Study the Past Monitor the Present Model the
Future
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Piecing Together a Picture of Climate History

• Ice Cores Gas, Isotopes, Dust
• Sediment Cores Pollen, Charcoal, Fossils
• Pack-rat Middens
• Tree-rings Ring width, Ring density,
  Isotopes, Fire scars
• Instrumental Record

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Climate is always changing.

• Just sometimes faster than at other times.

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Ice core data
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Global Temperature Trends
Black Instrumental Record 1861-1990 Others
Reconstructed from tree rings
From Jones et al. 2001 Science 292 662-667
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Global Temperatures
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Climate ChangeTemperatures

• Warming
• Night vs. Day
• Winter vs. Summer
• Elevation
• Latitude Poles vs. Equator

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Ocean/Atmosphere Interactions

• Warming Atmosphere Can hold more moisture
  Increased energy stronger storms
• Warming OceansEvaporate greater quantities of
  waterAlter locations and strength of currents

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NOAA GEOPHYSICAL FLUIDS DYNAMICS LABORATORY
TEMPERATURE PROJECTIONS (ºC)
WINTER
SUMMER
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Water

• Snow melt Earlier / more rapid
• Stream flow Dominated more by rain rather
  than snow More rapid rain related peaksLess
  summer flows

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Climate Change

• Temperatures
• Water
• Disturbance
• Vegetation Habitat

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Climate ChangeFireWhat might we expect?
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Havent Fire Regimes and Forests had to adjust to
a warming climate before?

• Never
• when accompanied by nearly a century of
• fire suppression!

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Fires have been ground fires, and easily
controlled. A trail will sometimes stop them.

• R.B. Wilson
• 1904
• Township descriptions of the lands examined for
  the proposed Trinity Forest Reserve, California.
  
• US Department of Agriculture, Bureau of Forestry,
  Washington, D.C.

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Of the hundreds of persons who visit the Pacific
slope in California every summer to see the
mountains, few see more then the immediate
foreground and a haze of smoke which even the
strongest glass is unable to penetrate.

• C. Hart Merriam
• 1898 Visit to Siskiyou County
• Chief, Division of Biological Survey
• From Morford 1984

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Where are we headed?

• Fire season getting longer.
• Fuels keep growing.
• Greater probability of intense fires.

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Mediterranean Climate

• Cool/wet Winters vegetation/fuel
• Warm/dry Summer annual fire season
• Lightning

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Fire Climate - Precipitation Patterns
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Red dots Lightning Caused Fires Blue dots
Human Caused Fires
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Climate Fire Regimes?

• TemperatureFire Frequency
• Moisture Fire Extent

Swetnam 1993 Chang 1999
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Tree-ring Based Fire Histories

• Mostly cover the period of
• 1600 to 1900
• Much colder than 20th Century.

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Tree-ring Evidence of Fire/Climate
Relationships Skinner, Taylor, Carleton, Stephens
Regions adapted from Trouet, Taylor, Carleton,
Skinner 2006 GRL
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Inches
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June 2008 Lightning Fires
Modis Image from NASA World Wind overlayed
on Google Earth
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33 Fire Scars
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California 4.5 to 12 million acres/yr Stephens
et al. 2007 FEM
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Blacks Mountain Exp. Forest
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1841
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Hayfork Study Area
Taylor Skinner 2003
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Hayfork Study Area
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Fire Occurrence Tree EstablishmentBlacks
Mountain Experimental Forest
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Stand Structure Species Composition Changes
over 20th Century
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Annual Area Burned11 Western States
From Arno Allison-Bunnell 2002
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20th Century Fire TrendsSierra NevadaArea Burned
1000s of Acres
Weatherspoon Skinner 1996
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20th Century Fire TrendsSierra NevadaArea
Burned by Cause
1000s of Acres
Weatherspoon Skinner 1996
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20th Century Fire TrendsSierra NevadaMax Fire
Size by Cause
1000s of Acres
Weatherspoon Skinner 1996
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Forest Restoration?

• Tree-ring Based Fire Histories
• Much colder than 20th Century.

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Forest Restoration?

• What Time Period?
• What is your goal? Structure
  Process/Function Resilience

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20th Century Fire Activity?
Sierra San Pedro Martir, Baja California
Skinner et al. 2008
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Resilience

• the capacity of a system to absorb disturbance
  and reorganize while undergoing change so as to
  retain essentially the same function, structure,
  identity, and feedbacks

Folke, C. and others 2004. Regime shifts,
resilience, and biodiversity in ecosystem
management. Annual Review of Ecology, Evolution,
and Systematics 35 557-581.
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Resilience

• Forested systems characterized by fire regimes of
  frequent, mostly low-moderate intensity fires,
  dominated by large, long-lived trees, are
  considered resilient if the forested landscape
  exhibits a generally forested condition,
  including larger trees, shortly following an
  event such as fire.

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Stand Structure Species Composition Changes
over 20th Century in Fire Regimes of Frequent,
Low-Intensity Fires
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Stand ScalePriorities for Fuels Assessments

• Surface Fuels
• Ladder Fuels
• Crown Fuels
• Large Fire Resistant Trees

Agee Skinner 2005 Basic principles of forest
fuel reduction treatments. Forest Ecology
Management 211 83-96
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The most potent factor in shaping the forest of
the region has been, and still is, fire. The
general character of the forest, ... in fact
almost every phase of its condition has been
determined by ... fire.

• J. B. Leiberg
• 1902
• Forest conditions in the northern Sierra Nevada,
  California.
• Professional Paper 8, Series H, Forestry, 5.
• US Geological Survey, GPO, Washington, D.C.

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Where are we headed?

• Fire season getting longer.
• Fuels keep growing.
• Greater probability of intense fires.

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Fire A Catalyst For Change?
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Predicting Fire Danger Indices

• Burning Index (BI)
• Energy Release Component (ERC)
• Haines Index (HI)
• Canadian Fire Weather Index (FWI)
• Palmer Drought Severity Index (PSDI)
• Snow Water Equivalence (SWE)

• Atlantic Multidecadal Oscillation (AMO)
• North Atlantic Oscillation (NAO)
• Pacific Decadal Oscillation (PDO)
• Pacific-North American Pattern (PNA)
• El Nino/Southern Oscillation (ENSO)

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Grid of All Dependent Variables

• BI
• ERC
• HI
• FWI
• PDSI
• SWE
• Fire History

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Example Burning Index
?
1977
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Thank You!