Lire le passé forestier dans un bourbier : histoire écologique et dynamique contemporaine d’une population marginale nordique d’érable rouge (Acer rubrum)

Abstract

ABSTRACT Populations at the edge of a species range are vulnerable to climate change. Studying their ecological history helps understanding resilience processes acting at the limit of the species’ tolerance envelope. In the mixedwood forest ecotone, several thermophilic species, such as white pine and red maple, reach the northern limit of their geographical range. Here we rely on macrofossil analysis of charcoal particles and plant macroremains of a forest hollow to reconstruct the local history of thermophilic species in a marginal red maple stand isolated within the mixedwood forest ecotone. Taxonomic identification and radiocarbon dating of charred particles and wood remains extracted along the peat accumulation profile indicated dominance of white pine during the Holocene Climate Optimum (6200 to 4300 cal yr BP). The fossil assemblage suggests the transition of a black spruce - feathermoss (>9500 to 6200 cal yr BP) to a balsam fir forest that developed after the decline of white pine (since 4300 cal yr BP). Red maple is not detected in the fossil assemblage suggesting a late arrival and/or expansion on the site, likely favored by anthropogenic activities and the climate warming ongoing since the end of the Little Ice Age.