Reconstructions of climate in the Holocene rely heavily on palaeoclimatic indicators such as altitudinal and latitudinal treeline movements inferred from direct (macrofossil) or indirect (pollen) evidence of sites distant from modern treelines. It is suggested here that long-term trends in tree regeneration on well-drained forest tundra sites (the transition zone between boreal forest and arctic tundra) may be used in a similar way. Charcoal found in soils of treeless zones or forest vegetation in the transition zone indicates respectively failure or success in post-fire tree regeneration. Since regeneration is influenced by climate, radiocarbon-dated charcoal can be used as a record of palaeoclimate. The paper reports a study of 4 regions in a S.-N. direction in the forest tundra of Quebec, from the limit of continuous forest to the treeline. It is suggested that the widespread occurrence of treeless sites is the result of late Holocene deforestation involving climate/fire interactions and that disjunct lichen/forest sites are the outcome of successful regeneration sometime during the last 1000 yr. This climatically induced process is acting at the site and species levels south of the present treeline.