Reconstruction of the long-term fire history of an old-growth deciduous forest in Southern Québec, Canada, from charred wood in mineral soils

Abstract

Charcoal particles are widespread in terrestrial and lake environments of the northern temperate and boreal biomes where they are used to reconstruct past fire events and regimes. In this study, we used botanically identified and radiocarbon-dated charcoal macrofossils in mineral soils as a paleoecological tool to reconstruct past fire activity at the stand scale. Charcoal macrofossils buried in podzolic soils by tree uprooting were analyzed to reconstruct the long-term fire history of an old-growth deciduous forest in southern Québec. Charcoal fragments were sampled from the uppermost mineral soil horizons and identified based on anatomical characters. Spruce (Picea spp.) fragments dominated the charcoal assemblage, along with relatively abundant wood fragments of sugar maple (Acer saccharum) and birch (Betula spp.), and rare fragments of pine (Pinus cf. strobus) and white cedar (Thuja canadensis). AMS radiocarbon dates from 16 charcoal fragments indicated that forest fires were widespread during the early Holocene, whereas no fires were recorded from the mid-Holocene to present. The paucity of charcoal data during this period, however, does not preclude that a fire event of lower severity may have occurred. At least eight forest fires occurred at the study site between 10,400 and 6300 cal yr B.P., with a dominance of burned conifer trees between 10,400 and 9000 cal yr B.P. and burned conifer and deciduous trees between 9000 and 6300 cal yr B.P. Based on the charcoal record, the climate at the study site was relatively dry during the early Holocene, and more humid from 6300 cal yr B.P. to present. However, it is also possible that the predominance of conifer trees in the charcoal record between 10,400 and 6300 cal yr B.P. created propitious conditions for fire spreading. The charcoal record supports inferences based on pollen influx data (Labelle, C., Richard, P.J.H. 1981. Végétation tardiglaciaire et postglaciaire au sud-est du Parc des Laurentides, Québec. Géographie Physique et Quaternaire 35, 345-359) of the early arrival of spruce and sugar maple in the study area shortly after deglaciation. We conclude that macroscopic charcoal analysis of mineral soils subjected to disturbance by tree uprooting may be a useful paleoecological tool to reconstruct long-term forest fire history at the stand scale.

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

“…According to recently published reports and this study, fires were frequent in the early Holocene in the current maple sites distributed across southern Quebec according both to macrocharcoal [23,27,30] (Figure 4) and micro-and mesocharcoal [25] data. The mid-Holocene was a period less-prone to fire occurrence both in the study area and the areas close to our Appalachian sites in the Saguenay [23] and the Quebec City [30] areas.…”

“…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]. Although realistic on biogeographical grounds, the fire/sugar maple connection during the Holocene as reported from pollen and microcharcoal data remains to be tested with direct evidence from botanically-identified macrofossil data including macrocharcoal.…”

Black (pyrogenic) carbon: a synthesis of current knowledge and uncertainties with special consideration of boreal regions

“…Figure 6 from Gavin (2003) shows how charcoal could be transported from organic to mineral horizons from fires at 2500 y and 1500 y before present. The importance of charcoal burial by tree uprooting also shown by Talon et al (2005), who used the charcoal fragments in podzolic soils to reconstruct fire history in an old-growth deciduous forest in southern Québec. On steeper slopes of British Columbia interior rainforest, charcoal is transported and buried mainly by shallow earth landslides resulting from loss of root strength after wildfires (Sanborn et al, 2006).…”

Reconstructing Holocene fire history in a southern Appalachian forest using soil charcoal

“…Radiocarbon dating of soil charcoal fragments has been used to establish the approximate age of fire events in tropical forests (Turner 1984, Piperno and Becker 1996, Hammond et al 2006, high-elevation forests in the Sierra Nevada and French Alps (Anderson and Smith 1997, Carcaillet 1998, Hajdas et al 2007, and old-growth Douglas fir-hemlock in the Pacific Northwest (Lertzman et al 2002, Gavin et al 2003, Higuera et al 2005). In the Eastern Deciduous Biome, stand-level fire history studies using soil charcoal have focused on old-growth maple/birch forests in southern Quebec (Talon et al 2005) and mixed hardwood forests in the Cumberland Plateau of middle Tennessee (Hart et al 2008). Here we present the first such stand-level study in forests of the Appalachian Mountains.…”