Millennial disturbance‐driven forest stand dynamics in the Eastern Canadian taiga reconstructed from subfossil logs

Gennaretti, Fabio, Arseneault, Dominique et Bégin, Yves (2014). Millennial disturbance‐driven forest stand dynamics in the Eastern Canadian taiga reconstructed from subfossil logs. Journal of Ecology, 102 . pp. 1612-1622.

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Summary :
1. Although wildfire is the main natural disturbance factor driving changes in the North American boreal forest, understanding how the fire history of the last millennium shaped the present‐day landscape diversity is a difficult task due to the lack of palaeoecological reconstructions with high spatial (few hundreds of square metres) and temporal (annual) resolutions.
2. We combined a detailed inventory of the present‐day lakeshore forest of two lakes of the Eastern Canadian taiga with the dendrochronological dating of the subfossil logs that accumulated in the littoral zones facing these shores. Our objective was to compare the millennial impact of wildfires among stands of various structures and compositions. Past stem densities and fire years were reconstructed from log recruitment rates and dating of charred logs.
3. Multivariate analysis of the present‐day lakeshore forest revealed three and two homogeneous shore segments per site (i.e. clusters). Cluster 1 at both sites exhibited denser forest, higher dead wood values and a higher percentage of balsam fir, a fire‐sensitive species.
4. In total, 426 and 611 subfossil logs (mostly black spruce) were crossdated over the last ˜1400 years. Their dendrochronological analysis confirmed that each lakeshore cluster, identified from the traits of the present‐day forest, experienced a specific fire history over the last millennium (i.e. 0–5 fires of variable severity) that locally influenced forest composition, tree density and growth. Each fire triggered a specific forest structure trajectory characterized by a different stem density and rate of recovery.
5. Synthesis. This study provides a long‐term perspective that helps explain how the present‐day landscape diversity in the Eastern Canadian taiga reflects the site‐specific fire history over the last millennium. Fires have caused persistent and cumulative impacts resulting in a progressive opening of the forest cover along with balsam fir exclusion. Present‐day landscapes are mosaics of forest stands characterized by different times since fire and different post‐fire forest structure trajectories. -- Keywords: Abies balsamea ; boreal forest ; dendrochronology ; determinants of plant Community diversity and structure, fire ecology ; paleoecology ; Picea mariana ; Québec ; successional trajectory

Type de document :	Article
Validation par les pairs :	Oui
Information complémentaire :	Ceci est la version révisée par les pairs de l'article suivant : Gennaretti, F., Arseneault, D. and Bégin, Y. (2014), Millennial disturbance‐driven forest stand dynamics in the Eastern Canadian taiga reconstructed from subfossil logs. J Ecol, 102: 1612-1622., dont la version finale est disponible ici: https://doi.org/10.1111/1365-2745.12315 Cet article peut être utilisé sans visée commerciale, en accord avec les termes et conditions d'utilisation des articles auto-archivés de Wiley. -- This is the peer reviewed version of the following article: Gennaretti, F., Arseneault, D. and Bégin, Y. (2014), Millennial disturbance‐driven forest stand dynamics in the Eastern Canadian taiga reconstructed from subfossil logs. J Ecol, 102: 1612-1622., which has been published in final form at: : https://doi.org/10.1111/1365-2745.12315 This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
Mots-clés :	Forêts boréales ; Taïgas ; Perturbations écologiques ; Feux de forêts ; Écologie des feux ; Paléoécologie ; Sapin baumier ; Abies balsamea ; Épinette noire ; Picea mariana.
Version du document déposé :	Post-print (version corrigée et acceptée)
Départements et unités départementales :	Département de biologie, chimie et géographie
Déposé par :	DIUQAR UQAR
Date de dépôt :	01 oct. 2020 16:00
Dernière modification :	06 juill. 2023 14:08
URI :	https://semaphore.uqar.ca/id/eprint/1627

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