Sugar maple (Acer saccharum) forests at their northern distribution limit are recurrently impacted by fire

Abstract

The sugar maple (Acer saccharum Marsh.) forest is a widespread temperate forest prevailing south of 48°N in Quebec. Windthrows are the principal disturbance maintaining the old-growth status of the forest supposedly since its postglacial establishment. Nonetheless, the presence of wood charcoal buried in several sugar maple forest soils attests to the occurrence of fire during the Holocene. In this study, we aimed to elucidate the long-term fire dynamics and species composition of three sites (Témiscamingue, Saguenay, and Gaspé peninsula) currently dominated by sugar maple situated at its northern range limit. The botanical identification and 14 C dating of charcoal fragments extracted from the soil surface and the mineral soil indicate that the development of the sugar maple sites was influenced by recurrent fires at least over the last 1000 to 3500 years. Two of the studied sugar maple stands are of recent origin, with the Témiscamingue forest being established after the most recent fire in the late 18th to early 19th centuries. Our data highlight the resilience of sugar maple forests in a disturbance regime dominated by frequent fires and suggest that the northernmost sugar maple forests are young ecosystems at the Holocene timescale.Résumé : Les érablières dominées par l'érable à sucre (Acer saccharum Marsh.) sont des forêts tempérées considérées comme une formation mature dominante du Québec méridional. Ces forêts se seraient maintenues en état de renouvellement perpétuel par la chablisation du couvert forestier depuis leur établissement à l'Holocène. La présence de charbons de bois dans le sol des érablières témoigne néanmoins de l'occurrence in situ du feu dans le passé. Nous avons évalué l'importance prise par les feux et les changements floristiques survenus dans trois stations (Témiscamingue, Saguenay et Gaspésie) depuis la déglaciation. L'identification botanique et la datation au 14 C de charbons montrent que les trois stations ont été sous l'influence d'un régime de feux fréquents depuis les derniers 1000 à 3500 ans. Au moins deux des trois érablières sont apparues récemment, dont l'érablière du Témiscamingue qui s'est formée à la suite d'un feu survenu à la charnière des 18 e et 19 e siècles. Nos données mettent en évidence la résilience des forêts d'érable à sucre évoluant sous un régime de feux fréquents et montrent que les érablières du Québec situées à leur limite d'aire nordique constituent de jeunes écosystèmes à l'échelle de l'Holocène.Mots-clés : Holocène, histoire des feux, forêt à feuillage décidu, limite de répartition nordique, érable à sucre, forêt boréale.

Sugar maple (Acer saccharum) at its northeastern range limit: a fire-resilient tree species

“…The same fire frequency is again observable in macrocharcoal datings from the beginning of the Holocene in the region situated in the countryside around Rimouski, in the Saguenay, as well as in the greater Quebec City region (Talon et al 2005;Pilon and Payette 2015;Payette et al 2016;2017). The Mont-St-Pierre sugar maple site, also located in the northern part of the Gaspé Peninsula, shows a fire history resembling that of Forillon during the last millennium, where 6-8 fires occurred at an interval of 120-150 years (Pilon and Payette 2015). Furthermore, the mid-Holocene does not seem to have been a period favorable to propagation of fires, based on the fire record in all of these regions.…”

“…The same paleofire tendencies characterize the Bas-StLaurent region, situated west of the Gaspé Peninsula, and is highlighted by peaks in microcharcoal abundance in several lakes at the beginning of the Holocene (Richard et al 1992). The same fire frequency is again observable in macrocharcoal datings from the beginning of the Holocene in the region situated in the countryside around Rimouski, in the Saguenay, as well as in the greater Quebec City region (Talon et al 2005;Pilon and Payette 2015;Payette et al 2016;2017). The Mont-St-Pierre sugar maple site, also located in the northern part of the Gaspé Peninsula, shows a fire history resembling that of Forillon during the last millennium, where 6-8 fires occurred at an interval of 120-150 years (Pilon and Payette 2015).…”

“…Sugar maple is tolerant of shade conditions of the forest environment (Forcier 1975;Bellefleur and Villeneuve 1984;Beaudet and Messier 1998). The species responds readily to local disturbances induced by windthrows and windsnaps (Canham 1985;Payette et al 1990), and also to larger disturbances caused by clearcut (Albert and Barnes 1987;Bannon et al 2015;Pilon et al 2018), ice storm (Beaudet et al 2007) and fire (Pilon and Payette 2015). Current shady and locally sun-exposed forest environments across the species range provide a diversified suite of favorable conditions for its regeneration, growth and survival across a continuum of stand disturbances (Nolet et al 2008).…”

Fire History of Appalachian Forests of the Lower St-Lawrence Region (Southern Quebec)

“…forests were considered ecosystems maintained at equilibrium [12] under the regime of canopy-gap dynamics [13][14][15]. However, field evidence suggests that sugar maple is adapted to various sun-and-shade regeneration environments [16] associated with logging [17][18][19], abandoned fields [20], and fire [21][22][23]. The rise and dominance of sugar maple communities deduced from pollen data have been associated with reduced fire activities, particularly during the mid-Holocene [24][25][26][27].…”

“…Given that macrocharcoal of sugar maple and other hardwood species as well as conifer species can be identified at the genus if not the species level, Figure 1. Location of SNR (Nicolas-Riou Seigneury) and RFD (Duchénier Faunal Reserve) sugar maple sites (red dots), and the other Rivière-Éternité (RIÉ) [23], Villeroy (VIL) and Ste-Françoise (STF) [30] sugar maple sites (red squares). Table 1.…”