Ages and isotopic signatures of peat cores from a boreal landscape, Interior Alaska

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Main Authors: Myers-Smith, Isla H, Harden, J W, Wilmking, Martin, Fuller, C C, McGuire, A David, Chapin, F Stuart
Format: Dataset Open Access
Language:en
Published: PANGAEA 2008
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author Myers-Smith, Isla H
Harden, J W
Wilmking, Martin
Fuller, C C
McGuire, A David
Chapin, F Stuart
author_facet Myers-Smith, Isla H
Harden, J W
Wilmking, Martin
Fuller, C C
McGuire, A David
Chapin, F Stuart
collection Datos científicos de ciencias marinas y ambientales
contents To determine the influence of fire and thermokarst in a boreal landscape, we investigated peat cores within and adjacent to a permafrost collapse feature on the Tanana River Floodplain of Interior Alaska. Radioisotope dating, diatom assemblages, plant macrofossils, charcoal fragments, and carbon and nitrogen content of the peat profile indicate ~600 years of vegetation succession with a transition from a terrestrial forest to a sedge-dominated wetland over 100 years ago, and to a Sphagnum-dominated peatland in approximately 1970. The shift from sedge to Sphagnum, and a decrease in the detrended tree-ring width index of black spruce trees adjacent to the collapse coincided with an increase in the growing season temperature record from Fairbanks. This concurrent wetland succession and reduced growth of black spruce trees indicates a step-wise ecosystem-level response to a change in regional climate. In 2001, fire was observed coincident with permafrost collapse and resulted in lateral expansion of the peatland. These observations and the peat profile suggest that future warming and/or increased fire disturbance could promote permafrost degradation, peatland expansion, and increase carbon storage across this landscape; however, the development of drought conditions could reduce the success of both black spruce and Sphagnum, and potentially decrease the long-term ecosystem carbon storage.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_817460
institution PANGAEA
language en
publishDate 2008
publisher PANGAEA
record_format pangaea
spellingShingle Ages and isotopic signatures of peat cores from a boreal landscape, Interior Alaska
Myers-Smith, Isla H
Harden, J W
Wilmking, Martin
Fuller, C C
McGuire, A David
Chapin, F Stuart
Alaska, USA; International Polar Year (2007-2008); IPY; PERM; Sampling permafrost; Tanana_R-plain
To determine the influence of fire and thermokarst in a boreal landscape, we investigated peat cores within and adjacent to a permafrost collapse feature on the Tanana River Floodplain of Interior Alaska. Radioisotope dating, diatom assemblages, plant macrofossils, charcoal fragments, and carbon and nitrogen content of the peat profile indicate ~600 years of vegetation succession with a transition from a terrestrial forest to a sedge-dominated wetland over 100 years ago, and to a Sphagnum-dominated peatland in approximately 1970. The shift from sedge to Sphagnum, and a decrease in the detrended tree-ring width index of black spruce trees adjacent to the collapse coincided with an increase in the growing season temperature record from Fairbanks. This concurrent wetland succession and reduced growth of black spruce trees indicates a step-wise ecosystem-level response to a change in regional climate. In 2001, fire was observed coincident with permafrost collapse and resulted in lateral expansion of the peatland. These observations and the peat profile suggest that future warming and/or increased fire disturbance could promote permafrost degradation, peatland expansion, and increase carbon storage across this landscape; however, the development of drought conditions could reduce the success of both black spruce and Sphagnum, and potentially decrease the long-term ecosystem carbon storage.
title Ages and isotopic signatures of peat cores from a boreal landscape, Interior Alaska
topic Alaska, USA; International Polar Year (2007-2008); IPY; PERM; Sampling permafrost; Tanana_R-plain
url https://doi.org/10.1594/PANGAEA.817460