uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/fdd383d39faac574627ed76034a1bbfe Wyatt Oswald https://orcid.org/0000-0001-6217-1831 David Foster https://orcid.org/0000-0003-1171-3762 Elaine Doughty Researcher Edward Faison Researcher Barbara Hansen Researcher 2023 English

We analysed lake-sediment pollen records from eight sites in southern New England to address: (1) regional variation in ecological responses to post-glacial climatic changes, (2) landscape-scale vegetational heterogeneity at different times in the past, and (3) environmental and ecological controls on spatial patterns of vegetation.

The eight study sites are located in southern New England in the states of Massachusetts and Connecticut. The sites span a climatic and vegetational gradient from the lowland areas of eastern Massachusetts and Connecticut to the uplands of north-central and western Massachusetts. Tsuga canadensis and Fagus grandifolia are abundant in the upland area, while Quercus, Carya and Pinus species have higher abundances in the lowlands.

Our analyses revealed a sequence of vegetational responses to climate changes occurring across southern New England during the past 14,000 calibrated radiocarbon years before present (cal yr BP). Pollen assemblages at all sites were dominated by Picea and Pinus banksiana between 14,000 and 11,500 cal yr BP; by Pinus strobus from 11,500 to 10,500 cal yr BP; and by P. strobus and Tsuga between 10,500 and 9500 cal yr BP. At 9500-8000 cal yr BP, however, vegetation composition began to differentiate between lowland and upland sites. Lowland sites had higher percentages of Quercus pollen, whereas Tsuga abundance was higher at the upland sites. This spatial heterogeneity strengthened between 8000 and 5500 cal yr BP, when Fagus became abundant in the uplands and Quercus pollen percentages increased further in the lowland records. The differentiation of upland and lowland vegetation zones remained strong during the mid-Holocene Tsuga decline (5500-3500 cal yr BP), but the pattern weakened during the late-Holocene (3500-300 cal yr BP) and European-settlement intervals. Within-group similarity declined in response to the uneven late-Holocene expansion of Castanea, while between-group similarity increased due to homogenization of the regional vegetation by forest clearance and ongoing disturbances.

The regional gradient of vegetation composition across southern New England was first established between 9500 and 8000 cal yr BP. The spatial heterogeneity of the vegetation may have arisen at that time in response to the development or strengthening of the regional climatic gradient. Alternatively, the differentiation of upland and lowland vegetation types may have occurred as the climate ameliorated and an increasing number of species arrived in the region, arranging themselves in progressively more complex vegetation patterns across relatively stationary environmental gradients. The emergence of a regional vegetational gradient in southern New England may be a manifestation of the increasing number of species and more finely divided resource gradient.

lakes paleoecology pollen region sediments vegetation dynamics LTER controlled vocabulary disturbance populations LTER core area Harvard Forest HFR LTER USA HFR default

This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.

Creative Commons Zero v1.0 Universal https://spdx.org/licenses/CC0-1.0.html CC0-1.0 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf185 Blood Pond (Dudley MA). Coordinates based on WGS84 datum. -71.9615 -71.9615 +42.08 +42.08 214 214 meter -13000 2010 genus Betula species spp. birch genus Carya species spp. hickory genus Fagus species spp. beech genus Picea species spp. spruce genus Pinus species spp. pine genus Quercus species spp. oak genus Tsuga species spp. hemlock complete Information Manager Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 hf-im@lists.fas.harvard.edu Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu

We collected sediment cores from three lakes in eastern and north-central Massachusetts (Berry East, Blood and Little Royalston Ponds). Pollen records from those sites were compared with previously published pollen data from five other sites. Multivariate data analysis (non-metric multi-dimensional scaling) was used to compare the pollen spectra of these sites through time.

Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu https://ror.org/059cpzx98 pointOfContact The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210. hf185-01-pollen-Blood.csv pollen hf185-01-pollen-Blood.csv 460656 1b398b68a418899cdc259a1404787703 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p18/hf185/hf185-01-pollen-Blood.csv cal.age.bp calibrated age before present in years number 0.0001 real NA missing value depth depth in sediment column centimeter 1 whole NA missing value taxa name of taxa name of taxa count number of pollen grains or spores of individual number 1 whole NA missing value 17446 hf185-02-age-Blood.csv age hf185-02-age-Blood.csv 1896 b13025753f6da9c7f9abc534dd87645d 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p18/hf185/hf185-02-age-Blood.csv depth depth in sediment centimeter 1 whole NA missing value cal.age.bp calibrated age before present (years; present=1950 AD) number 0.00000001 real NA missing value notes notes and methods of age determination; 210Pb=lead-210 dating; 14C=radiocarbon dating; Euro settlement=determined by rise in abundance of weedy and agricultural taxa notes and methods of age determination; 210Pb=lead-210 dating; 14C=radiocarbon dating; Euro settlement=determined by rise in abundance of weedy and agricultural taxa c14 un-calibrated radiocarbon years number 1 whole NA missing value error analytical error for 14C dates in years number 1 whole NA missing value 52 hf185-03-macrochar-Blood.csv macrochar hf185-03-macrochar-Blood.csv 396 f89d187e5a93d505a5dd67732ae613eb 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p18/hf185/hf185-03-macrochar-Blood.csv depth depth in sediment column centimeter 1 whole NA missing value pieces.cc number of macroscopic (greater than 180 microns) per cc numberPerCentimeterCubed 1 whole NA missing value 51 hf185-04-microchar-Blood.csv microchar hf185-04-microchar-Blood.csv 2832 59100028b4f3a517f7b7be9493c44f0b 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p18/hf185/hf185-04-microchar-Blood.csv depth depth in sediment column centimeter 1 whole NA missing value char.area area of charcoal pieces greater than 10 and less than 180 microns in length squareMillimeters 0.00001 real NA missing value exotic.char number of exotic marker grains encountered during charcoal analysis number 1 whole NA missing value pollen.sum number of pollen grains and spores of upland taxa encountered during pollen analysis number 1 whole NA missing value exotic.pollen number of exotic maker grains encountered during pollen analysis number 1 whole NA missing value exotic.added total number of exotic marker grains added to sample numberPerCentimeterCubed 1 whole NA missing value sed.vol volume of the sediment samples centimeterCubed 0.5 real NA missing value 75 historical paleological https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf184 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf186 numberPerCentimeterCubed