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Savanna fire impacts on regional and global climate

Savanna fire impacts on regional and global climate. William Sea. CSIRO Marine and Atmospheric & Land and Water Research Canberra.  Natural Resource Ecology Laboratory Colorado State University. 4 February 2008. Ozflux08. PhD Research Questions.

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Savanna fire impacts on regional and global climate

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  1. Savanna fire impacts on regional and global climate William Sea CSIRO Marine and Atmospheric & Land and Water Research Canberra  Natural Resource Ecology LaboratoryColorado State University 4 February 2008 Ozflux08

  2. PhD Research Questions Mortality:How do increases in tree mortality (juvenile and adult) change steady state woody basal area in a demographic-competition model compared with a traditional aggregated logistic model? Stochasticity:How does stochasticity in fire intensity and frequency impact woody dynamics relative to mean-field simulations? Initial Values:How do changes in initial values of basal area affect the steady state values (B*) in the demographic model compared with the logistic model? Competition Asymmetry:How do changes in the magnitude of asymmetric tree-grass competition lead to changes in steady state basal area values?

  3. Demographic-Competition Model Juveniles: (1) Adults: (2) Basal Area: (3) Grass Biomass: (4)

  4. Analytical Implicit Solutions Methods: Set each equation to zero. * Isolate critical bifurcation parameter, adult mortality (μA ), on the left side of equation relating all parameters and steady state basal area values (B*). Substitute in the full range of B* values and solve for μA. Basal area (B*) Plot μAvs B* .

  5. Effects of Stochastic Fire Mortality Biennial Burns (2 yr) Mean Adult mortality = 2% Juvenile mortality = 50 % Grass Biomass (green) Tree Basal Area (black) Normalized to 1 = max

  6. Postdoctoral Project Goal Improve the modelling of vegetation dynamic and emissions of aerosol and greenhouse gases from biomass burning of savannas in ACCESS • Stage 1: Compilation of data sets including global savanna tree cover, vegetation and soil carbon, and if possible seasonal variation. • Stage 2: Calibrate CASA-CNP using data. • Stage 3: Calculate emissions of aerosol particles, black carbon, CO2, Co, CH4 and N20 from savanna fires with frequency and extent based on remote sensing and fire load estimated from CASA-CNP. Run a global model to calculate radiative forcing based on savanna fire emissions.

  7. 2007 Fires in Australia

  8. Modis-derived global fire loss Vander Werf (2007)

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