1. School Research Conference, March 2009 Jennifer Wright Supervisors: M.Williams, G. Starr, R.Mitchell, M.Mencuccini Fire and Forest Ecosystems in the Southeastern USA Photo by Richard Bryant

2. Introduction Yellowstone fire in 1988 (picture from University of Utah Meteorological Department) Yellowstone in 1999, 11 years after fire ( picture from Dr. Robert Ruhf ) Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan…

3. Introduction Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan… 3 months after fire, biennial burning regime Longleaf pine forest, December 2008

4. Introduction What? To examine the influence of fire on carbon processes in a subtropical savanna - woodland over a soil moisture gradient. “…a better understanding of the effects of natural disturbances on C cycling is critical, particularly in light of alterations to disturbance regimes that may occur with global climate change” (Litton et al., 2004) Why? How? Development and testing of a modelling tool using 2 existing models (SPA2, GAPFIRE) and field data collection Where? Longleaf pine ecosystem of the South-eastern USA, fieldwork based at Joseph W. Jones Ecological Research Center, GA Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan…

5. Longleaf Pine Ecology 1 Regular burning Understory (dominated by wiregrass (Aristida stricta) Overstory dominated by longleaf pine (Pinus palustris) Fire suppressed Mid story of oaks developing in an area of fire suppression Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan…

6. Longleaf Pine Ecology 2 Mesic (wet) siteXeric (dry) site Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan…

7. Longleaf Pine Ecology 3 Pine early growth stage Low intensity fire Post fire pine saplings Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan… “Grass” stage Lasts up to 15 years Most carbon to roots

8. Why model? Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan… Carbon Dynamics Abiotic Factors Pine/oak dynamics Belowground processes UnderstoryBiodiversity Fuel Composition Fuel Load Fuel Distribution Climate Management Soil type Soil moisture Nutrient availability Fire External Forcing Biotic Factors

9. The Model Pines Oaks Understory Soil Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan… Savanna structureClosed canopy forest

10. Model Canopy conductance photosynthesis, leaf respiration Vegetation dynamics & disturbance Land-use and land-cover change Autotrophic and Heterotrophic respiration Phenology Turnover Solution of SEB; canopy and ground temperatures and fluxes Soil heat and moisture Surface water balance Atmosphere Fluxes Ecosystem dynamics Landscape dynamics Canopy conductance, photosynthesis Vegetation dynamics & disturbance Land use and land cover change AllocationPhenologyLitter production Nutrient cycles Surface temperatures and heat fluxes Soil heat and moisture Surface water balance Autotrophic & heterotrophic respiration Atmospheric forcing Radiation, H 2 O, CO 2 & heat fluxes Rapid processes (hours) Intermediate processes (days-weeks) Slow processes (years+) SPADALECGAPFIRE Williams et al, 2009 Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan… SPA2

11. Key Questions No Fire Large Fire Many small ground fires Fire (size indicates magnitude) Legend Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan… ? Time Living Biomass Carbon Is this possible? Carbon in living biomass in a fire-prone ecosystem Other considerations: - Soil carbon - Coarse woody debris - ecosystem GPP

12. Time Key Questions Time Soil Carbon GPP Coarse Woody Debris Time Living Biomass Carbon Time Total Ecosystem Carbon Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan…

13. The Plan… Make sure the models work in the longleaf pine ecosystem Make the models more specific Put the models together and make sure that works Use the model to explore the carbon dynamics in the longleaf pine ecosystem Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan… 3 2 1 4

14. Data needed to achieve The Plan Introduction Longleaf Pine Ecosystem Model Overview Questions The Plan… Already availableInitiatedFuture Long Term Ecological Monitoring Program Ecosystem Productivity Study Ford (2004) water use and productivity data Addington (2001) rooting, water use, productivity and leaf-level ecophysiological data for P. palustris. Jacqmain (1996) data on community composition and dynamics Eddy covariance towers at 3 sites (xeric, mesic and intermediate) Monthly hemispherical photographs and litterfall data MODIS LAI time series Further ecophysiological work, specifically on oak species and wiregrass Further data on rooting depth and patterns, specifically on oaks Biomass allometrics work Canopy structure and characterization work Eddy covariance tower at Red Dirt siteHemispherical photograph from January 09 (Baker Woods site)

15. Thank you! Any Questions?