Long-term fire history of maple (Acer) forest sites in the central St. Lawrence Lowland, Quebec

In the St-Lawrence lowlands, sugar maple (Acer saccharum Marsh.) is considered the dominant species of old-growth deciduous forests, whereas red maple (Acer rubrum L.) tends to dominate sites recently disturbed by logging and agricultural practices. Considering that the long-term influence of fire is not documented for such stands, we reconstructed the postglacial tree composition (as deduced from charcoal species) and fire history of a sugar maple stand (Ste-Francoise area) and a red maple stand (Villeroy area) located southwest of Quebec City, Canada. The sites are 10 km apart and show contrasting soil and landform features. Using botanical identification and ¹⁴C dating of soil macrocharcoal, we found that fire struck both maple stands 14--20 times since deglaciation. Most fires occurred in the early Holocene and during the last 2000 years, with the mid Holocene being a period with low fire frequency or no fires. During the last 1600 years, the Villeroy stand shifted from a Tsuga canadensis (L.) Carriere -- conifer forest to a mixed forest and, most recently, to a red maple stand as fire became more frequent, possibly due to human activities of the last 400 years. This study confirms the influence of fire on the development of maple forests. Fire should be considered as an important disturbance factor in the dynamics of temperate deciduous and mixed forests. (author)