Abstract

The Acadian forest is a mixed-wood forest covering the Canadian provinces of New Brunswick and Nova Scotia. Picea rubens (red spruce) is its signature species which has been prominent for circa 2,000 years. To our knowledge, no high-resolution pollen analysis has been done in New Brunswick, and no lacustrine charcoal analysis. We extracted a 124 cm surface core from Fish Lake, (46° 8’ 38.32’’N, 66° 53’ 12.64’’ W), near Fredericton, New Brunswick, Canada. A BACON age-depth model, based upon 4 14C and 15 210Pb dates, showed that the bottom of the core dated to AD 890. We performed a high-resolution pollen analysis on this core at a ~10 year resolution, with 125 samples in all. Over the last millennium, there were declines in Betula (birch), Tsuga canadensis (eastern hemlock) and Fagus grandifolia (American beech), together with increases in Pinus sp. (pine), Abies balsamea (fir) and Picea sp. (spruce), including P. rubens. CONISS showed that the Medieval Climate Anomaly (MCA – AD 900-1400), Little Ice Age (LIA – AD 1400 –1850), and the European settlement period were clearly demarcated in the pollen record. A rise in Ambrosia (ragweed) marked early Acadian French agriculture at ~AD 1680. The last 300 years of the European period showed increases in Poaceae (grasses), Ambrosia, and other herbs, and declines in Pinus sec. haploxylon (eastern white pine). Charcoal analysis showed that natural forest fires had a continuous presence over the past millennium. The paleo-fire record showed higher fire frequency during the MCA than in the LIA. WA-PLS was used to reconstruct spring temperatures. The reconstruction showed that the MWP had an average spring temperature of 3.2 °C, and the LIA had an average spring temperature of 2.2 °C.