NINETEEN BOGS FROM SOUTHERN QUEBEC

Abstract

The 19 pollen profiles from the Gaspé and the St. Lawrence Valley show close correlation with known facts in glacial geology of this region. Marine invasions and persistence of the Laurentian icecap prevented forest occupation until climate had warmed considerably. The warm period was followed by a deteriorating climate as shown by rise in spruce and fir. During the succeeding very warm period, spruce and fir became rare, pine increased in the Gaspé region, and hemlock and broadleaved trees associated with pine became important in the St. Lawrence Valley, while the forests on the lower Laurentian Shield were composed primarily of pine penetrated by hemlock and broadleaved genera as minor elements. During most recent times the climate has become colder. Spruce and fir show a decided peak, especially in the Gaspé and on the Shield, pine declined in all parts of Quebec, but broadleaved genera, including chestnut in some areas, became prominent in the St. Lawrence Lowland, while decline of hemlock and pine and increase of spruce, fir, and yellow birch mark the forests on the southern slopes of the Shield. Pollen profiles are favorably correlated with forest divisions of Halliday.