A 6 KA BP RECONSTRUCTION FOR THE ISLAND OF NEWFOUNDLAND FROM A SYNTHESIS OF HOLOCENE LAKE-SEDIMENT POLLEN RECORDS

A 6 ka reconstruction for the island of Newfoundland is presented in t he context of a synthesis of Holocene pollen records for twelve sites within or at the margin of the boreal forest, five of which are new. C limatic reconstruction is based primarily on representation of the maj or boreal taxa: balsam fir, spruce, birch and pine, with charcoal data for some sites. The period of greatest Holocene warmth began at 6 ka. Although temperatures at inland sites were at or close to modern valu es as early as 8.5-8.0 ka, it was not until 6 ka on the Avalon Peninsu la, in the southeast, and 5.5 ka in the north, that coastal sites regi stered expansion of more thermophilous taxa. Thus oceanic warming lagg ed terrestrial warming. Temperatures during the period of greatest war mth were no more than 1.0 degrees C higher than modern, based on fluct uations of the upper forest limit and post-Hypsithermal contraction of the range of indicator taxa. Fire importance increased after 6 ka as pine expanded, but moisture availability also increased. The first ind ications of cooling occurred on the coast at 4.5-4.0 ka, but at differ ent times after 4.0 ka inland; thus oceanic cooling led terrestrial co oling. The latest Holocene has been cool, moist and relatively free fr om fire.