Stable carbon isotopes as potential sea-level indicators in salt marshes, North Carolina, USA
Kemp, Andrew C.; Vane, Christopher H.; Horton, Benjamin P.; Culver, Stephen J.. 2010 Stable carbon isotopes as potential sea-level indicators in salt marshes, North Carolina, USA. The Holocene, 20 (4). 623-636. 10.1177/0959683609354302Before downloading, please read NORA policies.
We compared the use of δ13C values and C:N ratios from salt-marsh sediments to reconstruct relative sea level (RSL) with an established approach using foraminifera. Analysis of bulk-organic sediment and plant samples collected along transects at two sites in North Carolina, USA demonstrates that sediment δ13C values can be used to distinguish between Spartina alterniflora-dominated low marsh (C photosynthetic pathway, δ13C values from —17.6‰ to 16.1‰) and Juncus roemerianus-dominated high marsh (C 3 photosynthetic pathway, δ13C values from —28.2‰ to —21.8‰) environments. Juncus roemerianus plants undergo little decompositional change in δ13C (average 0.8‰), although there is a clear difference between Spartina alterniflora tissue and bulk-organic sediments (approximately 4‰). C:N ratios on bulk-organic sediment from freshwater upland and salt-marsh environments converge during early diagenesis, rendering them of little use in reconstructing RSL. The utility of δ13C values as a sea-level indicator is limited by the elevational range of C4 plants, making it difficult to recognize salt-marsh subenvironments and improve the precision of RSL reconstructions. Furthermore, Juncus roemerianus-dominated high marsh and freshwater upland sediments cannot be adequately distinguished with δ13C values.
|Programmes:||BGS Programmes 2010 > Land Use, Planning and Development|
|Additional Keywords:||Salt marshes, North Carolina, Carbon isotopes, Climate change|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||20 Jul 2010 13:36|
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