Stand Age Influence on Potential Wildfire Ignition and Spread in the Boreal Forest of Northeastern Canada

Erni, Sandy, Arseneault, Dominique et Parisien, Marc-André (2018). Stand Age Influence on Potential Wildfire Ignition and Spread in the Boreal Forest of Northeastern Canada. Ecosystems, 21 . pp. 1471-1486.

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Résumé

Although it has long been assumed that wildfire occurrence is independent of stand age in the North American boreal forest, recent studies indicate that young forestsmay influence burn rates by limiting the ignition and spread of fires for several years. Wildfires not only structure the stand-age mosaic of boreal landscapes, but also alter the likelihood and behavior of subsequent fires. Using a fire simulation model, we evaluated the effect of stand age on themagnitude and spatial patterns of burn probability (BP) in the boreal forest of northeastern Canada. Specifically, we assessed the stand age effect on the twoprocesses driving fire likelihood, ignition and spread, by simulating tens of thousands of fires under three fire regime scenarios that vary in terms of mean fire size and number of burned patches. Assuming minimal resistance to fire ignition and spread, where only the youngest stands ( £ 10 years) are resistant to burning, mean BP is reduced by 10%; in contrast, assuming maximum resistance, where stands up to 90 years old impede wildfires, mean BP can be reduced up to 85%. Although the resistance to ignition on BP is almost identical in magnitude to that of spread, it yields substantially different spatial arrangements of BP. Furthermore, stand age resistance reduces subsequent fire activity not onlywithin but also outside the perimeter of burned patches through a shadoweffect.Our results help to untangle the role of factors contributing to stand age resistance on wildfires and offernewinsights for improving the spatial mapping of fire likelihood. -- Keywords : wildfires ; burn probability ; stand age dependence ; landscape patterns ; boreal forest ; fire likelihood.

Type de document :	Article
Validation par les pairs :	Oui
Mots-clés :	Forêts boréales ; Canada (Nord-Est) ; Feux de forêts ; Incendies ; Potentiel ; Probabilités ; Age ; Peuplement ; Arbres.
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 :	02 oct. 2020 01:46
Dernière modification :	06 juill. 2023 14:13
URI :	https://semaphore.uqar.ca/id/eprint/1630

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