Erosion of modern terrestrial organic matter as a major component of sediments in fjords

TitleErosion of modern terrestrial organic matter as a major component of sediments in fjords
Publication TypeJournal Article
Year of Publication2017
AuthorsCui, X, Bianchi, TS, Savage, C
JournalGeophysical Research Letters
Volume442824441945245112168105110293225215662639493436151675187268234320723424507431438414191121427211539259
Issue345355903755111181-21212316171193141-2182341
Pagination1457 - 1465
Date PublishedApr-02-2018
Abstract

Fjords have recently been recognized as “hot spots” of carbon burial. In this study, we investigated organic carbon (OC) and biomarker radiocarbon values in fjord sediments from New Zealand. Our results showed that OC was mostly modern with the most aged OC in middle reaches of fjords, likely related to hydrodynamic sorting and inputs along adjacent slopes. Radiocarbon ages of sedimentary OC increased from north-to-south, consistent with the Fiordland regional gradients of lower fjord slopes and less rainfall. Our biomarker results suggested that lignin and long-chain fatty acids were preferentially linked with fresh terrestrial debris and degraded soil, respectively, likely due to their chemical and physical properties. Finally, we propose that fjords are a significant sink of modern OC, in contrast to large lowland coastal systems as a major sink of preaged OC. Overall, this study indicated that radiocarbon techniques are critical in investigating carbon dynamics in coastal systems.

URLhttp://doi.wiley.com/10.1002/2016GL072260http://onlinelibrary.wiley.com/wol1/doi/10.1002/2016GL072260/fullpdfhttps://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2F2016GL072260
DOI10.1002/2016GL072260