1. Gridded Biome-BGC Simulation with Explicit Fire-disturbance Sinkyu Kang, John Kimball, Steve W. Running Numerical Terradynamic Simulation Group, School of Forestry, Univeristy of Montan

2. Purpose Demonstrate Gridded Biome-BGC run in BOREAS. Illustrate Biome-BGC modification for explicit fire- disturbance simulation

3. Process of Gridded BGC Batch run of Biome-BGC combined with input and output module Using IDL (Interactive Data Language) Spatial & temporal data INI, EPC, MET file for point Biome BGC run Batch run of point Biome BGC Generate gridded outputs

4. Considering Explicit Fire-Disturbance Raw DataSize and location Before 1959: constant fire mortality After 1959: fire mortality from raw data

5. Generate fire grid Year cell[i,j] annual fire file Considering Explicit Fire-Disturbance 87 83 84 85 86

6. Considering Explicit Fire-Disturbance 1.0 (DIM) multiplier for shortwave radiation CO2_CONTROL (keyword - do not remove) 1 (flag) 0=constant 1=vary with file 2=constant, file for Ndep 286.923 (ppm) constant atmospheric CO2 concentration kco21862.txt (file) annual variable CO2 filename FIRE_CONTROL (keyword - do not remove) 1 (flag) 0=constant fire mortality 1=vary with file fire-5-14.txt (file) annual variable fire mortality (year fire_mortality) SITE (keyword) start of site physical constants block Modifed INI & EPC files Run Modified Biome-BGC ECOPHYS ENF-cool (wet conifer) 1 (flag) 1 = WOODY 0 = NON-WOODY ……………………………………………………. 0.005 (1/yr) annual whole-plant mortality fraction 0.005 (1/yr) mean annual fire mortality fraction 0.26(1/yr) annual carbon fraction consumed by fire 1.5 (ratio) (ALLOCATION) new fine root C : new leaf C 1.1 (ratio) (ALLOCATION) new stem C : new leaf C

7. ET (mm/y) & NPP (gC/m2/y) LAI (m2/m2) Daily fire mortality Constant fire mortality > 1959 < Explicit fire occurrence Internal fire-disturbance External fire-disturbance

8. Modification of Biome-BGC Biome-BGC v.411  47 source files  8 header files  2 library files In this study, even this small change required  modification of 7 source files  modification of 4 header files  addition of a new subroutine source file

9. Application to the Boreal Forest Biome Grid size (simulation unit): 66 columns and 60 rows Each simulation uses  i dentical land cover and soil property over the entire grid  identical spatial meteorological variable (1994~1996) Every simulation differs in  land cover types (DBF, Grass, DC, WC)  constant or varying ambient CO 2 and internal or external fire- disturbance  Nine climate change scenario (control,  2 o C,  20% precipitation) Total 108 cases of gridded Biome-BGC runs Experimental Design

10. 660km 300km Land Cover

11. Topography

12. Climate (3-yr mean) TmaxTmin PrecipitationRadiation

13. Sample Result 1 – Land cover DBFGrass DCWC

14. Sample Result 2 – CO2 WC, Const. CO2 WC, Increasing CO2 Difference Const. CO2 – Increasing CO2

15. Sample Result 3 - Fire WC, Increasing CO2 Difference External fire – Increasing CO2 WC, External fire

16. Sample Result 4 – Climate Change PRCP*TEMP: PRCP(-1,0,+1), TEMP(-1,0,+1), EX: +1-1 (1.2*prcp & -2 of Temp.) 00 +10 -10 +1+1 +1-1 -1+1 -1-1 DBF, Const. CO2

17. Difference to Control (precipitation, temperature) (1,0)-(0,0)(-1,0)-(0,0) (1,1)-(0,0)(1,-1)-(0,0) (-1,1)-(0,0)(-1,-1)-(0,0) Climate Scenario

18. Future consideration  Combining Biome-BGC with an explicit routing hydrology model (DHSVM?)  Model Initialization Spin-up run: initialize soil and vegetation state variable at steady-state condition time consuming process Extrapolation from field or satellite measurement: satellite-driven LAI  initialize vegetation carbon variables using allometry rules (Landsat & MODIS in watershed and regional scale) field measurement  initialize soil variables using empirical relationships (ex. Soil depth – topographic index,White et al. 1988)