Ages and isotopic signatures of peat cores from a boreal landscape, Interior Alaska
Cobertura |
MEDIAN LATITUDE: 64.640745 * MEDIAN LONGITUDE: -148.333500 * SOUTH-BOUND LATITUDE: 64.640620 * WEST-BOUND LONGITUDE: -148.333700 * NORTH-BOUND LATITUDE: 64.640870 * EAST-BOUND LONGITUDE: -148.333300 * DATE/TIME START: 2001-07-01T00:00:00 * DATE/TIME END: 2004-08-30T00:00:00 |
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Data(s) |
31/07/2008
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Resumo |
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. |
Formato |
application/zip, 2 datasets |
Identificador |
https://doi.pangaea.de/10.1594/PANGAEA.817460 doi:10.1594/PANGAEA.817460 |
Idioma(s) |
en |
Publicador |
PANGAEA |
Direitos |
CC-BY: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted |
Fonte |
Supplement to: Myers-Smith, IH; Harden, JW; Wilmking, M; Fuller, CC; McGuire, A David; Chapin, F Stuart (2008): Wetland succession in a permafrost collapse: interactions between fire and thermokarst. Biogeosciences, 5(5), 1273-1286, doi:10.5194/bg-5-1273-2008 |
Palavras-Chave | #-; 137Cs; 137Cs std dev; 210Pb; 210Pb std dev; 210Pb unsup; 210Pb unsup std dev; 226Ra; 226Ra std dev; Age; Age, 14C AMS; Age, dated; Age, dated material; Age, dated standard deviation; Age, standard deviation; Age dated; Age std dev; Alaska, USA; Caesium 137, standard deviation; Caesium 137 activity per mass; Carbon, organic, per area; Corg area; Cs137 in pCi/g; d13C; d13C std dev; d14C; d14C std dev; Date/Time; DATE/TIME; Dated material; delta 13C; delta 13C, standard deviation; delta 14C; delta 14C, standard deviation; Depth; DEPTH, sediment/rock; International Polar Year (2007-2008); in transect; IPY; ka BP; #0 means <modern; Lab; Laboratory; Lead 210; Lead 210, standard deviation; Lead 210, unsupported; Lead 210, unsupported, standard deviation; LLNL = Lawrence Livermore National Laboratory Centre for AMS; KCC = UC Irvine W. M. Keck Carbon Cycle AMS facility; Location; PERM; Radium 226; Radium 226, standard deviation; recalculated to Bq; recalculated with 1 Ci = 3.7x10**10 Bq; Sample ID; Sampling permafrost; Standard deviation; Std dev; supported; Tanana_R-plain |
Tipo |
Dataset |