FIGURE 3 (continued) A4.
(4), the ability to date macrofossils allowed a high-resolution late glacial record. The record starts at 15,700 cal. B.P. with an open subalpine forest mainly represented by Tsuga mertensiana. Between 15,250 and 14,850 cal. B.P., a closed montane forest with primarily Abies amabilis is recorded. This record is interpreted to represent a warming compared to the previous interval. Between 14,850 and 14,500 cal. B.P., Pseudotsuga dominated in the forest, and an increase of Tsuga heterophylla indicates warmer climatic conditions. Between 14,500 and 14,250 cal. B.P., a return to subalpine forests indicates a reversal to a colder climate. At Gordon Lake in Oregon (5), between 15,500 and 14,500 cal. B.P., T. mertensiana is recorded together with Picea and Pinus, suggesting a cooler climate.
In the northeastern Atlantic region, the Allamuchy, New Jersey, and Linsley Ponds, Connecticut, records (7) show the first organic sedimentation at ca. 15,000 cal. B.P. A Picea-Quercus assemblage is recorded, attesting to a cool and humid climate. At Jackson Pond in Kentucky (8), with a lower age of older than 16,000 cal. B.P., a Pinus-Picea zone is recorded with an increase of deciduous taxa. The environment is defined as an open, taiga-like woodland. At Browns Pond in Virginia (12), Alnus, Pinus, Picea, and Abies are recorded prior to 15,000 cal. B.P. At ca. 13,000 cal. B.P., deciduous tree taxa increase—mainly Ostrya, Carpinus, and Quercus. This change indicates a rapid warming and increase in moisture. At Camel Lake in Florida (13), the co-occurrence of Carya and Picea between 17,000 and 14,800 cal. B.P.
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