Data from: Unearthing forest history: integrating soil charcoal macrofossils and pollen reveals delayed forest responses to Holocene climate change in boreal–temperate ecotone

Soil samples were immersed for 12-24 h in a 1% NaOH solution to break up aggregates, then washed under running water through 4-mm and 2-mm mesh sieves. Charcoal fragments retained on the sieves were manually extracted under a stereomicroscope, dried at room temperature, and weighed using an analytical balance. Particles were identified to the lowest possible taxonomic level under an episcopic microscope.

Samples were prepared and dated at the André E. Lalonde AMS Laboratory (University of Ottawa, Ottawa, Canada) or at the 14C radiochronology laboratory of the Centre d’études nordiques (Université Laval, Québec, Canada), with measurements performed at the Keck Carbon Cycle AMS Facility (University of California, Irvine CA, USA).