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Harvard Forest Symposium Abstract 2008

  • Title: Post-glacial history of vegetation and fire in southwestern Connecticut
  • Primary Author: Wyatt Oswald (Emerson College)
  • Additional Authors: Elaine Doughty (Harvard Forest); Edward Faison (Highstead, Inc.); David Foster (Harvard Forest); Barbara Hansen (University of Minnesota - Twin Cities)
  • Abstract:

    Sedimentary records from two study sites in Redding, Connecticut provide new insights into the post-glacial history of ecosystems in southern New England. Analysis of pollen in a core from Highstead Swamp reveals changes in moisture balance and vegetation during the late-glacial interval; pollen and charcoal records from Umpawaug Pond show shifts in forest composition and fire regimes since 10,000 years before present (yr BP). A transition from spruce- to pine-dominated vegetation at the beginning of the Holocene (11,500 yr BP) appears to be associated with a transition from pond to swamp sediments and vegetation, consistent with a decline in effective moisture seen elsewhere in the region. Following the early-Holocene period of abundant pine, forests in the Redding area featured high prevalence of oak; high values of charcoal influx indicate that fire was an important process during the middle Holocene. Oak pollen percentages declined abruptly from 55% to 35% at 3700 yr BP, accompanied by a drop in charcoal influx. These changes, perhaps associated with increasing moisture during the late Holocene, are consistent with other evidence for a link between oak abundance and fire occurrence. Charcoal values increase after 1000 yr BP, decline somewhat at the time of European settlement, then rise sharply to reach a peak 100 yr BP. European forest clearance and agricultural activities are clearly represented by declines in arboreal pollen percentages and elevated abundance of herbaceous taxa.

  • Research Category: Historical and Retrospective Studies