1 / 29

Immediate Changes Carbon Emissions, Tree Mortality Short Term Changes

Fire Severity: Amount of Change Following Fire (Percent Combusted). Immediate Changes Carbon Emissions, Tree Mortality Short Term Changes Erosion, Water Quality, Nutrient Availability Long Term Changes Future Flammability, Animal Browse.

neo
Download Presentation

Immediate Changes Carbon Emissions, Tree Mortality Short Term Changes

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fire Severity: Amount of Change Following Fire (Percent Combusted) • Immediate Changes Carbon Emissions, Tree Mortality • Short Term Changes Erosion, Water Quality, Nutrient Availability • Long Term Changes Future Flammability, Animal Browse

  2. Fire Severity: Amount of Change Following Fire (Percent Combusted) • Reconstructed Organic Matter (C&N) Pools Plot Scale; Quantitative; Effort=High • Composite Burn Index (CBI) Plot Scale; Semi Quantitative; Effort=Medium • Normalized Burn Ratio (NBR) Remote Sensing; Semi Quantitative; Effort=Low

  3. Fire Severity: Amount of Change Following Fire (Percent Combusted) How do we measure something that burned away?

  4. Biomass Reconstruction • Adventitious roots on black spruce trees grow at the surface of the organic soil • Roots are still visible after fire • Post-fire measurements can reconstruct pre-fire organic soil depth and C and N pools • Aboveground tree measurements, visual estimates, plus allometric equations used to reconstruct canopy green moss dead moss fibric humic

  5. Organic Soil Reconstruction Adventitious root Mean offset between adv. root and moss surface = 3.2 ± 0.3 cm

  6. Organic Soil Reconstruction • Measure depth & horizons of remaining post-fire organic soil • Adventitious root collar: height above burn (correct for deeper burning under trees) • soil core samples analyzed by horizon for bulk density, [C] and [N] (burned layers reconstructed from soil measurements in unburned)

  7. Canopy Reconstruction • Measure tree density and basal area • Visually estimate %Combustion for: needles, fine branches, coarse branches and cones • Black spruce allometric equations used to estimate quantity of canopy fine fuels • ~50% C • 0.4 - 1% N

  8. Composite Burn Index (CBI) • A scaled index to visually quantify and standardize fire effects over large areas. • Five strata • CBI scale: Low (0.5-1) Moderate (1.0-2.0) High (2.0-3.0)

  9. How does CBI compare to %combustion estimates? 100 80 60 %mass combustion 40 20 0 1 1.5 2 2.5 3 Total CBI scores Organic soil Canopy R2= 0.14, P<0.02 R2= 0.63, P<0.001 • Mean combustion was 64% • CBI significantly • positively related to • % mass combustion • CBI better correlated with organic soil combustion

  10. How does CBI compare to C emissions? 8 6 4 C emissions kg/m2 2 0 1 1.5 2 2.5 3 Total CBI score Organic soil R2= 0.44, P<0.001 Canopy R2= 0.14, P<0.03 • mean canopy and soil C emissions were 0.4 and 1.5 kg/m2 • CBI significantly • positively related to • % C lost • CBI better correlated • with organic soil C emissions

  11. How well does CBI correlate with our fire severity estimates?

  12. Summary • Adventitious root method is a good proxy for pre-fire organic soil height • Correct adventitious root measurements for deeper burning at tree, and for offset between root and organic soil surface height • CBI is a great estimator of % mass lost, and pretty good for C emissions • CBI is a better predictor for organic soil mass and C emissions, explaining from 45-64% of the variation

  13. Yukon Charley 1999 Fire start mid-June NBR 9-Sept CBI-NBR trend: R2 = 0.81, n=32 R2 = 0.64, n=47 Boundary 2004 Fire start mid-June NBR 6-Sept CBI-NBR trend: R2 = 0.30, n=32 R2 = 0.43, n=28 R2 = 0.29, n=73 2 Upland Black Spruce Burns

  14. dNBR = 672 dNBR = 797 dNBR = 913

  15. Lessons Learned • Remote sensing estimates best across wide range of severity • Unreliable to estimates at high fire severity • Estimates should be calibrated by vegetation type • Solar elevation/topography problems

  16. Field Estimates : CBI (0 to 3)

  17. How do we measure something that burned away? Using the adventitious root method to measure fire severity

  18. Measurementsat unburned sites: understory Root collar height Measurementsat burned sites: understory • Depth of post-fire organic soil including horizons • adventitious root collar height above burn • soil core samples analyzed by horizon for bulk density, [C] and [N] Adventitious root offset: Distance between high adventitious root and green moss 1. Dead moss 2. Fibric 3. Humic

  19. Mineral soil 1.Green moss 2. Brown moss 3. Fibric 4. Humic unburned sites four horizons:

  20. Does the adventitious root methodwork? 8 6 Frequency 4 2 0 0 > 0 <-6 to <0 to -1 <-5 to -6 <-4 to -5 <-1 to -2 <-2 to -3 <-3 to -4 Root collar offset values (cm) • Root collar height corresponds to organic soil height • add 3.2 cm • pre-fire organic soil • depth= post-fire depth + Root collar height + Root Collar offset

  21. Adventitious root height Green Moss Brown Moss Fibric Humic Mineral soil • Adventitious roots on black spruce trees grow at the surface of the organic soil • Roots are still visible after fire • We can reconstruct pre-fire organic soil depth and C and N pools Adventitious roots Moss +Adventitious root height + Depth of post-fire soil organic layer = Pre-fire soil organic layer depth Fibric Humic Mineral soil

More Related