Differentiating climatic and successional influences on long-term development of a marsh

By: , and 



Comparison of long—term records of local wetland vegetation dynamics with regional, climate—forced terrestrial vegetation changes can be used to differentiate the rates and effects of autogenic successional processes and allogenic environmental change on wetland vegetation dynamics. We studied Holocene plant macrofossil and pollen sequences from Portage Marsh, a shallow, 18—ha marsh in northeastern Indiana. Between 10 000 and 5700 yr BP the basin was occupied by a shallow, open lake, while upland vegetation consisted of mesic forests of Pinus, Quercus, Ulmus, and Carya. At 5700 yr BP the open lake was replaced rapidly by a shallow marsh, while simultaneously Quercus savanna developed on the surrounding uplands. The marsh was characterized by periodic drawdowns, and the uplands by periodic fires. Species composition of the marsh underwent further changes between 3000 and 2000 yr BP. Upland pollen spectra at Portage Marsh and other sites in the region shifted towards more mesic vegetation during that period. The consistency and temporal correspondence between the changes in upland vegetation and marsh vegetation indicate that the major vegetational changes in the marsh during the Holocene resulted from hydrologic changes forced by regional climate change. Progressive shallowing of the basin by autogenic accumulation of organic sediment constrained vegetational responses to climate change but did not serve as the direct mechanism of change.

Publication type Article
Publication Subtype Journal Article
Title Differentiating climatic and successional influences on long-term development of a marsh
Series title Ecology
DOI 10.2307/2265782
Volume 77
Issue 6
Year Published 1996
Language English
Publisher Wiley
Contributing office(s) Great Lakes Science Center
Description 14 p.
First page 1765
Last page 1778
Online Only (Y/N) N
Additional Online Files (Y/N) N
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