Holocene vegetation and climatic history of Prince Edward Island, Canada

Abstract

The vegetation and climate of the Holocene of Prince Edward Island are reconstructed from pollen analysis of four Sphagnum peat bogs, Portage and East Bideford Bogs in the west and Mermaid and East Baltic Bogs in the east. The discussion is based largely on percentage data supported by pollen influx estimates.The earliest recognizable vegetation was tundra-like with nonarboreal birch, willow, Artemisia, and upland grasses and sedges. The vegetation changed remarkably within a short period, from tundra at 10 000 years BP, to forest–tundra (spruce – nonarboreal birch association) between 10 000 and 8000 years ago, to pine at or shortly after 8000 years ago. Hemlock arrived 7000 years ago and dominated along with white pine from about 6500–4500 years BP. Beech came in about 3400 years ago and formed part of a hemlock–beech–birch association up until modern times. Sharp increases in weeds and grasses and declines in hemlock, birch, and beech denote European settlement approximately 100–150 years ago.A gradual warming tend is inferred for the period prior to about 8000 years BP, but rapid climatic improvement took place shortly after 8000 years ago corresponding with the pollen transition from spruce to pine. Maximum temperatures (close to 8.5 °C) were reached approximately 4000 years ago when the mean annual temperature may have been almost 2.5 °C warmer than present. Deterioration of the climate occurred at approximately 3000 and 1500 years ago, coinciding with increases in spruce, Ericaceae, and Sphagnum, and a decrease in pine.