The distribution of 75 lake and bog sites, from which pollen stratigraphical evidence relevant to the late Quaternary of Newfoundland has been obtained, is presented. The detailed records of lithology, pollen and diatoms, supplemented by geochemical data, are discussed for three of the sites -Southwest Brook Lake, Woody Hill Brook Pond and Leading Tickles -and interpretations made are based on vegetational history, relative climatic changes and extent of ice cover. Radiocarbon data from 14 sites are summarised. A summary chart of Late-glacial environmental changes, including a qualitative palaeotemperature curve, is provided.

A 6 ka reconstruction for the island of Newfoundland is presented in the 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. Climatic reconstruction is based primarily on representation of the major 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 values as early as 8.5-8.0 ka, it was not until 6 ka on the Avalon Peninsula, in the southeast, and 5.5 ka in the north, that coastal sites registered expansion of more thermophilous taxa. Thus oceanic warming lagged terrestrial warming. Temperatures during the period of greatest warmth were no more than 1.0°C higher than modern, based on fluctuations 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 indications of cooling occurred on the coast at 4.5-4.0 ka, but at different times after 4.0 ka inland; thus oceanic cooling led terrestrial cooling. The latest Holocene has been cool, moist and relatively free from fire.La reconstitution a été faite à partir des données polliniques holocènes tirées de 12 sites (dont 5 nouveaux) situés à l'intérieur de la forêt boréale ou à sa marge. La reconstitution climatique est d'abord fondée sur la représentation des principaux taxons boréaux : le sapin baumier, l'épinette, le bouleau et de pin, avec données sur charbon à certains sites. La période la plus chaude de l'Holocène a commencé à 6 ka. Si les températures atteignaient les valeurs modernes ou en étaient près dès 8,5-8,0 ka à l'intérieur de l'île, ce n'était pas avant 6 ka dans la péninsule d'Avalon, au sud-ouest, et à 5,5 ka au nord que les sites côtiers ont enregistré l'expansion des taxons plus thermophiles. Ainsi, le réchauffement océanique a suivi le réchauffement terrestre. Les températures au cours de la période la plus chaude étaient plus élevés d'à peine 1°C que maintenant, évaluées sur la base des fluctuations de la limite altitudinale de la forêt et la réduction post-hypsithermale de la gamme des taxons indicateurs. L'importance des feux s'est accrue après 6 ka avec l'expansion du pin, mais l'humidité a aussi augmenté. Les premières indications d'un refroidissement se sont manifestées sur la côte vers 4,5-4,0 ka, et à différentes périodes après 4 ka à l'intérieur. Ainsi, le refroidissement océanique a entraîné le refroidissement terrestre. L'Holocène le plus récent a été frais, humide et relativement exempt de feux de forêts.Die Rekonstruktion wird im Kontext der Synthèse von Holozân-Pollenbelegen von zwôlf Plâtzen innerhalb oder am Rand des nôrdlichen Nadelwaldgùrtels vorgestellt, von denen fùnf neu sind. Die Klima-Rekonstruktion stùtzt sich vor allem auf das Vorkommen der hauptsàchlichen borealen Taxa: Balsam-tanne, Fichte, Birke und Kiefer, mit Kohledaten fur manche Plàtze. Die wàrms...

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Synopsis Palynological evidence confirms that the Glen Roy-Loch Laggan proglacial lakes were impounded by ice of the Loch Lomond (Late Devensian) readvance. The highest stage of the lakes persisted until the time of the juniper pollen zone; the lowest stage had disappeared by the time of the beginning of the birch pollen zone. Drainage from the Pattack basin continued to discharge eastward through the Feagour, the lowest of the lake overflow channels, until the time of the birch-hazel pollen zone.

Two radiocarbon-dated pollen profiles from the eastern Avalon Peninsula suggest late déglaciation (probably no earlier than 9700 BP at the coast), followed by a brief period of tundra vegetation. After 9300 BP a rich shrub tundra at lower elevations was invaded by spruce, balsam fir and tree birch until at ca 8400 BP the vegetation was an open woodland. The forest remained open for the next 3000 years; evidence of fire and the continuous presence of Populus suggest drier and warmer conditions than at present. The period of maximum warmth, ca 5400-3200 BP, saw the closing of the forest cover, a rise in the level of the tree limit in the interior upland and an increase in precipitation. After 3200 BP decreasing temperatures resulted in a lowering of the tree limit. The climatic changes inferred for the Avalon Peninsula are compared with those inferred from palaeo-environmental studies along the eastern North American seaboard from Baffin Island to New England. A sequence of changing controls on the regional atmospheric circulation during the Holocene is suggested.