270 likes | 375 Views
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 10 th 2012. Fire. Credits: SOPFEU. Historical logging.
E N D
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
Fire Credits: SOPFEU
Historical logging Credits: Archives Nationales du Québec
Landclearing Credits: Archives Nationales du Québec
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 ?
Study area Elevation (m) < 2 K people > 10 K people
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
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
Impact of logging • Balsam fir (A. balsamea) (+) • Black spruce (P. mariana) (-) • White birch (B. papyrifera) (no effect) • Trembling aspen (P. tremuloides) (-)
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
Questions ? yan.boucher@mrnf.gouv.qc.ca