11 Paleolimnological Reconstructions: New Insights from the Tried and True to the Unique and New (Posters)

Thursday, 31 March 2016
8:00 AM - 5:30 PM
Exhibit Hall

ORGANIC RICH DEPOSITS FROM A SOUTHERN APPALACHIAN WETLAND INDICATE CARBON SEQUESTRATION POTENTIAL AND SITE STABILITY OVER THE LAST MILLENNIUM

Paper number: 11-4
Program: Theme Sessions
Time: 8:00 AM – 5:30 PM

Authors

Abstract

Organic-rich sediments from wetlands in the southern Appalachian Mountains have been used to record Holocene climate variability. Wetlands make up 5-8% of terrestrial land surfaces but account for storage of 20-30% of the Earth’s carbon (Mitsch et al. 2013). This demonstrates the efficiency of wetland systems to sequester carbon and to partially offset the historical increase in carbon dioxide (CO2) due to fossil fuel combustion. An unstudied wetland has been recently discovered within the Mills River Watershed area in North Carolina. A soil core obtained using a Dutch auger from Pilot Cove Wetland provides a multi-proxy, paleo-environmental record, and provides insight into carbon sequestration potential for the last 1,300 cal yrs BP. The core was sub-sampled at 5-cm intervals for analysis of bulk carbon, nitrogen, and stable carbon isotope-ratios. Additionally, three samples were submitted for radiocarbon age determinations. Environmental proxies were examined for trends concurrent with climate variability over the past millennium (Medieval Warming and The Little Ice Age). These proxies indicate stable conditions during these climatic events. C/N and d13C showed very little fluctuation and their average values indicate a stable system for the past 1,300 cal yrs BP, the maximum age of the wetland indicated from the basal radiocarbon age determination. Carbon sequestration (SCAR) values indicate the wetland stores approximately 2.6 tons C/yr, representing a total storage capacity over 3,000 metric tons for the entire wetland. The stable proxy signal for the wetland suggests that the site may not have experienced the effects of the Medieval Warming or the Little Ice Age climatic events. Alternately, it may suggest that the wetland was buffered (e.g. beaver activity?) in some way if these climatic events did indeed affect the region. Additional cores should be collected, and organic-rich proxy indicators should be integrated with other techniques (pollen fossil or fire history studies) in order to complement the extant analyses.

Geological Society of America Abstracts with Programs. Vol. 48, No. 3

doi: 10.1130/abs/2016SE-273409

© Copyright 2016 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.