Summary
Published in Ecosystems, 21: 1183-1195. https://link.springer.com/article/10.1007/s10021-017-0211-3
Balsam fir (Abies balsamea) and black spruce (Picea mariana) forests are the main conifer forest types in the North American boreal zone. The coexistence of the two species as well as their respective canopy dominance in distinct stands raises questions about the long-term evolution from one forest type to the other in relation to environmental factors including climate and stand disturbance. We tested the hypothesis that repetitive fire events promote the succession of balsam fir forests to black spruce forests and vice versa. Post-fire chronosequences of one black spruce (BSP) and one balsam fir (BFI) site were reconstructed based on the botanical composition and ¹⁴C-dated soil macro-charcoals. The results support the hypothesis of successional dynamics. The BSP site has been affected by fire for the past 7600 years, whereas the BFI site, after having been affected by several fires during the first-half of the Holocene, evolved in a fire-free environment for the last 4400 years. Periods of fire activity facilitated the dominance of black spruce forests. The cessation of fires around 4400 cal. years BP on the BFI site marks the beginning of the transition from black spruce to balsam fir stands. This succession is a long process, due to the ability of black spruce to regenerate by layering in the absence of fire. The resulting balsam fir stands are ancient and precarious ecosystems, since fire generally leads to the return of black spruce. The increase in balsam fir to the detriment of black spruce in boreal forests is a response to a decrease in fire frequency.
Sector(s):
Forests
Categorie(s):
Scientific Article
Theme(s):
Forest Ecology, Forestry Research, Inventory
Departmental author(s):
Author(s)
COUILLARD, Pierre-Luc, Serge PAYETTE, Martin LAVOIE et Mathieu FRÉGEAU
Year of publication :
2018
How to get the publication :
Available at the Direction des inventaires forestiers
Keywords :
Chronosequences, Abies balsamea, boreal forest, fire disturbance, Holocene, Picea mariana, soil charcoal, succession
