SS3.09 Climate-Lake Interactions
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
LiniA, University of Vermont, Burlington VT, USA, alini@zoo.uvm.edu
Dahlen, D, , Paul Smith's College, Paul Smiths NY, USA, dahlend@paulsmiths.edu
Kruge, M, A, Southern Illinois University, Carbondale IL, USA, kruge@geo.siu.edu
 
MULTI-DISCIPLINARY ANALYSIS OF LATE-GLACIAL AND EARLY-HOLOCENE ECOSYSTEM CHANGES: A CASE STUDY FROM NORTHERN NEW ENGLAND LAKES
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The climatic changes associated with the last Glacial-Interglacial transition had profound ecological impacts which were recorded in lake sediments. In order to determine how and at what rates lacustrine ecosystems were established in newly created post-glacial lakes, we have applied an array of geochemical (delta-13C, delta-15N, %C, %N, C/N, HI and OI) and biological (pollen and diatoms) analytical techniques in sediments from four northern New England (USA) lakes. A sharp increase in organic matter content and a significant decline in organic matter delta-13C values characterize the oldest intervals of the analyzed cores. We interpret this pattern as the combined result of landscape revegetation and the onset of primary productivity within the study lakes. The biological indicators (pollen and diatoms), which show substantial shifts associated with lake water chemistry changes and catchment-vegetation processes, support this hypothesis. Yet, our data indicate that even on a local scale the response of different lakes to environmental change is not identical. Regional differences in the climatic history and watershed geomorphology and chemistry play a major role in determining timing and rates of ecosystem development.