DOI: 10.5061/dryad.cvdncjtg2
title: Data from: Early departures and delayed arrivals: Holocene dynamics of temperate tree species in the boreal temperate ecotone

description: Understanding historical dynamics of peripheral populations over the
 Holocene provides key insights to anticipate species responses to ongoing
 global changes. A marginal stand at the leading edge of sugar maple (Acer
 saccharum) range was hereby investigated to infer the Holocene dynamics of
 sugar maple, red maple (Acer rubrum), eastern white pine (Pinus strobus),
 three prominent temperate tree species of the boreal-temperate forest
 ecotone in eastern Canada. Soil macrofossil charcoal analysis of 25,595
 charred wood particles revealed that white pine is detected at this
 marginal temperate forest site since the early-Holocene, red maple since
 the mid-Holocene, and sugar maple since the late-Holocene.  The
 transition from the warmer mid-Holocene to the cooler late-Holocene was
 marked by a decrease of white pine, which was expected because the overall
 bioclimatic envelope of temperate species shifted southward in response to
 lower mean temperatures of the Neoglacial. In contrast, the abundance of
 sugar and red maples increased during the cool late-Holocene
 period.  There was a significant lag between the establishment of
 maples, whereby the rustic red maple was found since the warmer
 mid-Holocene, while the cold intolerant sugar maple was only detected
 during the cooler late-Holocene. A shift in the fire regime, a disruption
 of coniferous priority effects in the soil, as well as the introduction of
 shared mycorrhizal fungi might tentatively explain late establishment of
 maples and the migration lag between the two species.  Synthesis:
 As temperate tree species require warmer temperatures than boreal species,
 some thermophilous species, such as white pine, increased in abundance at
 their northern edge during historically warmer periods. Our data reveals
 that not all temperate species behaved accordingly: maples were scarce
 during the warm mid-Holocene, while their abundance increased during the
 cool late-Holocene. A migration lag suggests that earlier arrival of
 generalist species such as red maple might be required to facilitate later
 establishment of specialists such as sugar maple. The historic decoupling
 between macroclimatic trends and temperate species range shift sheds new
 light on the potential responses of the boreal-temperate ecotone facing
 modern-day anthropogenic climate change.
description: # Data from: Early departures and delayed arrivals: Holocene dynamics of
 temperate tree species in the boreal temperate ecotone. A MSExcel
 spreadsheet including data used to analyze tree-size structure, grid
 sampling, charcoal diversity, and radiocarbon dates in 6 plots and 10
 transects of a marginal leading-edge sugar maple population in the
 northern part of the boreal-temperate forest ecotone in eastern Canada. ##
 Description of the Data and file structure Sheet 1 - Metadata. Provides
 details about the location of the study plots. Sheet 2 - Tree size
 structure. At each plot (n = 6), every tree was identified to the species
 level, its state was reported as alive, dead standing or dead fallen, and
 its diameter at breast height (DBH) was measured. Based on this
 measurement, basal area was calculated for each tree. Sheet 3 - Grid
 sampling. Sampling locations of grid-based sampling design. Number of
 charcoal fragments per sampling site and presence or absence (P/A) of Acer
 sp., A. rurbum, A. saccharum, and Pinus strobus from forest soil samples.
 Site information for soil sampling sites, including coordinates, slope
 orientation (°) and percent (%), and elevation (masl). Number of locations
 where living A. rubrum, A. saccharum, and P. strobus observed at points
 around grid sampling locations. Note the five locations where no forest
 soil was sampled (T4-4, T5-4, T6-9, and T7-10) because of the presence of
 a body of water. Despite the lack of soil sampling, observation of living
 target species individuals was still conducted. Sheet 4 - Charcoal
 diversity. Number of charcoals found per species/class per sampling site.
 Sheet 5 - Radiocarbon dates. Radiocarbon data of associated charcoal
 particles. Includes lab identification from the Center for Northern
 Studies and the Keck Carbon Cycle laboratories. Charcoal taxonomic
 identification and radiocarbon dating. Calibration data in the form of 2
 sigma/standard deviation intervals, associated probability interval and
 median age. ## Sharing/access Information Links to other publicly
 accessible locations of the data: None Was data derived from another
 source? NO If yes, list source(s):