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Climate Change and Forest Fire Activity in Canada


Climate Change and Forest Fire Activity in Canada B.J. Stocks, M.D. Flannigan, B.M. Wotton, B.D. Amiro, and J.B. Todd Natural Resources Canada Canadian Forest Service – PowerPoint PPT presentation

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Title: Climate Change and Forest Fire Activity in Canada

Climate Change and Forest Fire Activity in Canada
  • B.J. Stocks, M.D. Flannigan, B.M. Wotton, B.D.
    Amiro, and J.B. Todd
  • Natural Resources Canada Canadian Forest Service

Presentation to Senate Standing Committee on
Agriculture and Forestry April 10, 2003 Ottawa,
Circumboreal Forest Fire Activity
  • Annual burned area 5-15 million hectares
  • Primarily Canada, Russia and Alaska
  • Russian stats underestimated should be 5 to 10
    times higher
  • Area burned shows great inter-annual variability
  • Continental climate, extreme weather/fire danger
    conditions, multiple ignitions, and closed canopy
    forests are main drivers of boreal fire activity

Boreal Fire Importance/Characteristics
  • Dominant disturbance regime, natural essential
    to ecosystem maintenance, C cycling, biodiversity
  • Sensitive to climate change major carbon budget
    implications - 40 of terrestrial C in boreal
  • High fuel consumption, fast spread rates,
    sustained high intensity levels, towering
    convection columns (upper troposphere) with
    long-range smoke transport potential

Canadian Fire Statistics
  • Incomplete prior to 1970
  • lt certainty further back in time
  • Now 8000 fires, 2.8 million ha/yr
  • 500 million annually
  • Area burned is highly episodic
  • 0.7 to 7.6 million ha
  • Level of protection issue
  • Protect resources vs natural fire
  • Lightning fires
  • 35 of total fires /85 AB
  • Fire size
  • 3 of fires are gt200 ha (used in Large Fire
  • Remainder suppressed early
  • Represent 97 of area burned

Large Fire Database (LFDB)
  • Fires gt200 ha post-1950 nationally
  • Polygons with attributes (fire size, cause, start
    and end dates etc.) from fire management agencies
  • 1980s fires in central Canada illustrated
  • Updated annually working back in time with
    satellite imagery

Lightning/Human-Caused Fires
  • Most lightning fires in north, H-C along travel
  • Generally lightning fires grow larger
    detection/access issue
  • Lightning fire contribution to area burned
    increasing in recent decades

Actioned/Non-Actioned Fires
  • Many fires allowed to burn naturally, mainly in
  • Management decision based on values-at-risk
  • Constitutes 50 of area burned in Canada

LFDB Fire Size Distribution by Ecozone
Greatest area burned in boreal and taiga zones
of west-central Canada where unsuppressed fire
is common and fire climate most severe
Larger size-class fires, although less frequent,
account for most of area burned
Carbon Release Through Fire
  • Direct release to atmosphere averages 27 Tg C/yr
    (20 of Canadas fossil fuel emissions) -
    preliminary estimate - need further
    severity/decomposition work
  • Younger forests weaker C sinks than mature
  • Takes 20-30 years to fully recover after fire
    (confirmed from flux tower, aircraft and
    satellite measurements)

Disturbances and the Carbon Budget
Note rise in natural disturbances (fire and
insects) post 1970
Corresponding decrease in C sink strength of CDN
forest post-1970
Anticipated Changes in Seasonal Fire Danger and
Fire Season Length
Fire season length increases by 10 to 50 days by
Seasonal fire danger increases by 50-100 by 2090
Anticipated Fire Impacts
  • Increase in weather conditions conducive to fires
  • More frequent and severe fire activity
  • Projected impacts
  • More area burned, shorter fire return intervals
  • Younger age class structure
  • Ecosystem boundary/vegetation shifting
  • Less terrestrial C storage
  • Impacts on forest industry/communities
  • Health/pollution issues
  • Positive feedback to climate change (gtGHG
  • Need to quantify impacts in order to assess
  • Adaptation will be required
  • Ongoing CFS climate change/fire research
    addressing impacts and adaptation in
    collaboration with provinces/territories
  • Funding through Green Plan, Climate Change Action
    Fund, Action Plan 2000 and CRAs with provinces

Adapting to Increasing Fire Activity
  • Local scale
  • Community protection (FIRESMART)
  • Regional scale
  • Pilot fuelbreaks project break up fuel
    continuity to limit fire effects on fiber
  • Level of protection effectiveness studies cost
    of maintaining status quo with increasing risk,
    protect less and permit more natural fire
  • National scale
  • Cannot mitigate fire impacts across whole boreal
  • Adapt based on values-at-risk
  • Evaluate the impacts of an increased fire regime
    for policy-makers

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