1. Historical and physiographical determinants of tree species distribution in human-dominated boreal landscapes
Yan Boucher, Pierre Grondin and Isabelle Auger
97 th Annual meeting of the Ecological society of America
June 10th 2012

2. Fire
Credits: SOPFEU

3. Historical logging
Credits: Archives Nationales du Québec

4. Landclearing
Credits: Archives Nationales du Québec

5. Objectives
(1) How has land-use history of the last 150 years have influenced stand-replacing disturbance dynamics in the southern boreal forest of Québec, Canada ?
(2) How have stand-replacing disturbance dynamics and physiography controlled the present-day tree species composition ?
(3) How could this information be used in a context of ecosystem-based management and CC adaptation ?

6. Study area

7. Study area
Elevation (m)
< 2 K people
> 10 K people

8. Historical setting

9. Fire history:

10. Fire history:

11. Fire history:

12. Fire history:

13. Fire history reconstruction

14. Logged area over time

15. Logged area over time

16. Logged area over time

17. Disturbances regime
The elevation gradient has dramatically influenced disturbance dynamics
The fire regime has been considerably influenced by settlement
Logging as extensively affected the study area

18. Present-day forest analysis
Present-day forest composition
Cover dominated by
Balsam fir (A. balsamea)
Black spruce (P. mariana)
White birch (B. papyrifera)
Trembling aspen (P. tremuloides)
Transition matrix species vs environmental variables
Logistic regression analysis

19. Species distribution and elevation

20. Composition vs. fire history

21. Composition vs. fire history

22. Composition vs. fire history

23. Composition vs. fire history

24. Composition vs. soil variables

25. Impact of logging Balsam fir (A. balsamea) (+)
Black spruce (P. mariana) (-)
White birch (B. papyrifera) (no effect)
Trembling aspen (P. tremuloides) (-)

26. Take-home messages
Historical ecology is key to understanding the present and anticipating the future
Trembling aspen proliferation is related to fire history and physiography, rather than logging activities
Anticipated change in the fire regime could favor trembling aspen and other fire-adapted species
Long-term perspectives are needed about the impact of landuse and stand-replacing disturbances

27. Questions ?