69 Paleolimnological Studies of Climate Variability and Environmental Response (Posters)

Tuesday, 21 March 2017
1:30 PM - 5:30 PM
Grand Ballroom, 17th Floor

A 1900-YEAR MULTI-PROXY PALEOENVIRONMENTAL RECONSTRUCTION OF PISECO LAKE, ADIRONDACK MOUNTAINS, NEW YORK

Paper number: 69-3
Program: Theme Sessions
Time: 1:30 PM – 5:30 PM

Authors

Abstract

Analyses of lake sediments can be used to reconstruct past environmental conditions at a local to regional scale and show evidence of modern and prehistoric human-environment interactions. Paleolimnological studies in the Adirondack Mountains of New York have primarily focused on natural conditions and historical human impacts on the environment over the past 200 years. Piseco Lake, a 1163 hectare lake located in the southern Adirondack uplands of New York, has archaeological evidence of prehistoric human activity, which may also show in the sediment record. We present multi-proxy analyses of sediments collected from Piseco Lake spanning approximately the last 1900 years to reconstruct past ecological conditions and provide possible evidence of prehistoric human activity. Our proxy analyses include fossil pollen to reconstruct past vegetation patterns and detect any cultivar pollen, microscopic and macroscopic charcoal to detail the fire history of the area, and bulk sedimentary geochemical analyses (loss on ignition; δ13C, δ15N, and C: N ratios) to identify changes in nutrient dynamics, carbon cycling, and terrestrial vegetation. The pollen record indicates the area has been primarily dominated by Betula (birch), Picea (Spruce), Pinus (pine), and Tsuga (hemlock), and a recent significant rise in Poaceae (grasses) and Ambrosia (ragweed) most likely associated with European settlement in the area. Significant spikes in the raw macroscopic charcoal data appear around approximately 450–600 B.P., and within the past 200 years. Three state campgrounds were open to the public in the early to mid-1900s likely contributing to increased fire activity. The pre-European increase in charcoal may be the result of increased fire frequency due to a changing climate, or possibly prehistoric human activity, however correlations with other forthcoming proxies used in this study are required to detect additional environmental changes and make more detailed interpretations.

Geological Society of America Abstracts with Programs. Vol. 49, No. 2

doi: 10.1130/abs/2017NE-290084

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