Climatic changes in southern Connecticut recorded by pollen deposition at Rogers Lake

Thumbnail Image

Persistent link to this item

View Statistics

Journal Title

Journal ISSN

Volume Title


Climatic changes in southern Connecticut recorded by pollen deposition at Rogers Lake

Published Date






Rates of deposition of pollen grains throughout late- and postglacial time were determined from the pollen concentration in radiocarbon-dated sediment. Changes by a factor of 5 or more for all except rare pollen types from one level to the next were considered significant indication of changes in the pollen input to the lake, reflecting changes in the pollen productivity of the surrounding vegetation. Low pollen deposition rates in the oldest sediments reflect the prevalence of tundra vegetation between 14,000 and 12,000 years ago. An increase in the rate for tree pollen occurred 12,000 years ago, when boreal woodland became established. The rates continued to increase until a sudden sharp rise for white pine, hemlock, poplar, oak, and maple pollen 9,000 years ago marked the establishment of forest, similar perhaps to modern forests of the northern Great Lakes region. Pine pollen rates declined 8,000 years ago, and deciduous tree pollen became dominant. Ragweed pollen was deposited at relatively high rates 8,000 years ago, reflecting changes in the vegetation associated with the "prairie period" recorded in the Great Lakes region at this time. Subsequent changes in pollen deposition rates reflect the immigration of beech (6,500 years B.P.), hickory (5,500 years B.P.), and chestnut (2,000 B.P.) to southern Connecticut. During the past few hundred years pollen deposition rates reflect changes in the vegetation caused by disturbance by European settlers. Throughout much of postglacial time the pollen assemblages deposited at Rogers Lake are different from assemblages known from modern sediment. This makes climatic interpretation difficult and suggests that the forest associations of the region as they are recognized now are of quite recent origin.



Related to



Series/Report Number

Funding information

Isbn identifier

Doi identifier

Previously Published Citation

Davis, Margaret B. "Climatic Changes in Southern Connecticut Recorded by Pollen Deposition at Rogers Lake." Ecology 50.3 (1969): 409-22.

Suggested citation

Davis, Margaret B.. (1969). Climatic changes in southern Connecticut recorded by pollen deposition at Rogers Lake. Retrieved from the University Digital Conservancy,

Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.