Parallel climate and vegetation responses to the early Holocene collapse of the Laurentide Ice Sheet

Parallel changes in lake-level and pollen data show that the rapid decline of the Laurentide Ice Sheet (LIS) between 10,000 and 8000 cal yr BP triggered a step-like change in North American climates: from an ice-sheet-and-insolation-dominated climate to a climate primarily controlled by insolation....

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Bibliographic Details
Main Authors: Bryan Shumana, Patrick Bartleinb, Nathaniel Logara, Paige Newbya, Thompson Webb Iiia
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2001
Subjects:
MAP
1988
Bartlein et al
1998
Webb et al
1993
Hudson
Hudson Bay
Low Lake
Webb
Ice Sheet
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.580.8423
http://www.geo.brown.edu/georesearch/esh/QE/Publications/QSR2002/BShuman/ParallelPesponses/ParallelResponses.pdf
Description
Summary:Parallel changes in lake-level and pollen data show that the rapid decline of the Laurentide Ice Sheet (LIS) between 10,000 and 8000 cal yr BP triggered a step-like change in North American climates: from an ice-sheet-and-insolation-dominated climate to a climate primarily controlled by insolation. Maps of the lake-level data from across eastern North America show a reorganization of climate patterns that the pollen data independently match. Raised lake-levels and expanded populations of moist-tolerant southern pines (Pinus) document that summer monsoons intensified in the southeastern United States between 9000 and 8000 cal yr BP. Simultaneously, low lake-levels and an eastward expansion of the prairie illustrate an increase in mid-continental aridity. After the Hudson Bay ice dome collapsed around 8200 cal yr BP, lake-levels rose in New England, as populations of mesic plant taxa, such as beech (Fagus) and hemlock (Tsuga), replaced those of dry-tolerant northern pines (Pinus). Available moisture increased there after a related century-scale period of colder-than-previous conditions around 8200 cal yr BP, which is also recorded in the pollen data. The comparison between pollen and lake-level data confirms that vegetations dynamics reflect climatic patterns on the millennial-scale.

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