slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Ecological Context of Climate Impacts on Fire: Wildland Fire Area Burned in the Western U.S. 1916-2003 PowerPoint Presentation
Download Presentation
Ecological Context of Climate Impacts on Fire: Wildland Fire Area Burned in the Western U.S. 1916-2003

Loading in 2 Seconds...

play fullscreen
1 / 34

Ecological Context of Climate Impacts on Fire: Wildland Fire Area Burned in the Western U.S. 1916-2003 - PowerPoint PPT Presentation


  • 386 Views
  • Uploaded on

Ecological Context of Climate Impacts on Fire: Wildland Fire Area Burned in the Western U.S. 1916-2003 Jeremy Littell with Don McKenzie and Dave Peterson

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Ecological Context of Climate Impacts on Fire: Wildland Fire Area Burned in the Western U.S. 1916-2003' - lotus


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Ecological Context of Climate Impacts on Fire:Wildland Fire Area Burned in the Western U.S. 1916-2003

Jeremy Littell

with Don McKenzie and Dave Peterson

slide2

“Actually, the Forest Service where I work has sort of changed its mind about forest fires, and so I don’t say, ‘Only you can prevent forest fires’ anymore.”

“We’re more of a faith-based Forest Service now. So we feel that if there is a forest fire, maybe there was supposed to be one. Maybe we should pray for it to stop. It’s not up to us to play fire fighter.”

-Smokey the Bear, Prairie home Companion, 16 April 2005

95-97% of the area burned is burned by 3-5% of the fires, right?

context 20 th century area burned
Context: 20th Century Area Burned
  • Wildland-fire area burned: policy and resource management metric
  • WFAB ecologically imperfect
  • Are there useful, ecologically interesting relationships between climate and this data?

Data compiled from multiple sources (NIFMID)

20 th c fire and climate in the west

Statistical prediction

Westerling et al. 2003. BAMS.

20th C. Fire and Climate in the West

Mechanism  response

McKenzie et al. 2004. Conservation Biology

scaling responses and drivers compromise
Scaling Responses and Drivers: Compromise
  • Scale of Fire Data:
    • Annual State WFAB
    • Monthly 1° x 1° WFAB
    • To annual eco-regions
  • Scale of Climate Data
    • Monthly HCN
    • Match to eco-regions
    • Seasonal for several climate divisions:
objective ecologically specific meso scale fire climatology
Objective: Ecologically-specific, Meso-scale Fire Climatology
  • Goal: Develop ecosystem-specific diagnostic climate-fire relationships for western U.S.
  • Strategy: Reconstruct wildland fire area burned for as many western U.S. eco-provinces as possible.
  • Method: Evaluate climate-fire relationships for reconstructed area-burned by eco-province.
reconstructing eco province area burned from state and grid data
Reconstructing Eco-province Area Burned from State and Grid Data
  • Scale fire datasets to compatible spatial and temporal resolution.
  • Logarithmic regression models, training period is 1980-2000:

Log (Cascade Mixed (gridcells))= log (WA + OR)

  • Use modeled relationship to hind-cast Cascade Mixed for full 1916-2003 dataset.
seasonal climate aggregated hcn climate divisions
Seasonal Climate: Aggregated HCN Climate Divisions
  • Temperature, Precipitation, PDSI
    • Annual
    • Winter (ONDJFM)
    • “Growing Season”: (AMJJAS)
    • Summer: (JJAS)
  • PCA Aggregation
reconstructing eco province area burned from state and grid data19
Reconstructing Eco-province Area Burned from State and Grid Data
  • Scale fire datasets to compatible spatial and temporal resolution.
  • Non-linear, gamma-specific regression models, training period is 1980-2000:

Cascade Mixed (gridcells)= WA + OR, specify log link and σ2 ~μ2

  • Use modeled relationship to hind-cast Cascade Mixed for full 1916-2003 dataset.
slide25

*

* 1-(residual deviance/null deviance)

1980 2000 reconstructions vs climate
1980-2000 Reconstructions vs. Climate

Reconstructed Forest-Dominated

Ecoprovince Fire Time Series vs. climate variables

Antecedent precipitation seems to be more important than temperature

in forested systems during the model calibration period.

1916 2003 reconstructions vs climate
1916-2003 Reconstructions vs. Climate

Reconstructed Forest-Dominated

Ecoprovince Fire Time Series vs. climate variables

1980 2000 reconstructions vs climate28
1980-2000 Reconstructions vs. Climate

Reconstructed Grassland/Shrubland/Desert Dominated

Eco-province Fire Time Series vs. climate variables

As antecedent favor vegetation growth, fire area burned increases.

This is consistent with fuel or fuel AND climate limited systems.

1916 2003 reconstructions vs climate29
1916-2003 Reconstructions vs. Climate

Reconstructed Grassland/Shrubland/Desert Dominated

Eco-province Fire Time Series vs. climate variables

caveats
Caveats
  • Is the state-level data correctly normalized for reporting area in the early 20th century?
  • Is the proportion of area burned attributable to climate (vs. land use, vegetation dynamics, or fire exclusion) reasonably stationary?
summary
Summary
  • Eco-province wildland fire area burned is strongly influenced by climate between 1980 and 2000.
  • Reconstructions of 1916-2003 eco-province area burned indicate that similar but weaker relationships occur for the entire period.
  • Climate has exerted a detectable influence on 20th century wildland fire regardless of other influences.
conclusion
Conclusion
  • Climate  fire impacts are ecologically-dependent, and vary because of combined influences of seasonality, ecosystem vegetation, and climate regime.
  • Meso-scale, mechanism response approaches are useful in evaluating these relationships.
prospectus
Prospectus
  • Cross-validation to improve confidence about uncertainty.
  • Investigation of ocean/atmosphere controls on climate “supply” in extreme fire years.
  • Attribution of unexplained residual deviance in eco-province/climate models
  • Future extrapolation given future climate scenarios and constraints of eco-provinces
acknowledgements
Acknowledgements
  • Tony Westerling and Tom Swetnam