1. Shrubs in the CLM-DGVM Sam Levis LMWG meeting March 2006

2. (Sturm et al. BioScience 2005)

3. Motivation Shrub density increasing in tundra Shrub albedo < grass albedo (leaf & stem) Diff. morphology (eg height) affects albedo of snow-covered sfcs

4. CLM has shrubs! (when vegetation is prescribed) Broadleaf Deciduous (Boreal & Temperate) Broadleaf Evergreen (Temperate)

5. % BDS Boreal % Broadleaf Deciduous Shrubs (Boreal) courtesy of Peter Lawrence SATELLITE DATA

6. Activating Shrubs in the DGVM 1.Bioclimatic limits: IBIS-DGVM uses GDD 0 >100 But when DGVM is defined CLM can only put C3 grass in tundra…

7. Tundra 68ºN 149ºW PFT COVER

8. Activating Shrubs in the DGVM 1.Bioclimatic limits: IBIS-DGVM uses GDD 0 >100 shrubs behave too much like trees 2.C allocation to leaves, stems, roots 3.Light competition with trees 4.Drought & fire tolerance

9. Do we need higher PFT resolution? Kaplan et al. (2003) Tundra PFTs Cold Shrubevergreen Cold Graminoid or Forbsummergr. Cushion Forbevergreen Epstein et al. 2000 Longer list…

10. Extras

11. Tundra 68ºN 149ºW

12. % C3 Grass Arctic % C3 Grass (Arctic) courtesy of Peter Lawrence SATELLITE DATA

13. % BET Boreal % Broadleaf Evergreen Trees (Boreal) courtesy of Peter Lawrence SATELLITE DATA