Status: this preprint was under review for the journal BG. A final paper is not foreseen.
The Holocene Evolution of a Sedimentary Carbon Store in a Mid Latitude Fjord
Craig Smeaton,Xingqian Cui,Thomas S. Bianchi,Alix G. Cage,John A. Howe,and William E. N. Austin
Abstract. Fjord sediments are recognized as hotspots for the burial and storage of organic carbon, yet little is known about what drives the formation of these coastal carbon stores and how this has altered over time. Here we show that fjords can act as sustained hotspots for carbon burial and storage over Holocene timescales. Further we investigate the role of North Atlantic climate and humans in the evolution of a coastal carbon store using sediment records from a temperate Scottish fjord. Our findings indicate that climate and anthropogenic activity have independently driven increases in terrestrial carbon to the marine environment. When both these drivers were coupled, the terrestrial response was pronounced and the relative proportion of terrestrial OC in the marine sediments increases from 5 % up to 70 %. We hypothesize that sustained human disturbance through the late Holocene sensitized the catchment to abrupt climate reorganizations. The results highlight the importance of fjords for carbon burial and the significance of terrestrial carbon subsidy to the long-term carbon store.
This preprint has been withdrawn.
How to cite. Smeaton, C., Cui, X., Bianchi, T. S., Cage, A. G., Howe, J. A., and Austin, W. E. N.: The Holocene Evolution of a Sedimentary Carbon Store in a Mid Latitude Fjord, Biogeosciences Discuss. [preprint], https://doi.org/10.5194/bg-2019-163, 2019.
Received: 29 Apr 2019 – Discussion started: 20 May 2019
The sediments in fjords are known to be important sites for locking carbon away for long periods of time (thousands of years) but the processes by which climate and human activity influence the development of these coastal carbon stores is poorly understood. A record of long-term sediment burial from a Scottish fjord allows us to investigate the role that humans and climate has played. The results indicate that both climate and humans have an impact on terrestrial ecosystems.
The sediments in fjords are known to be important sites for locking carbon away for long periods...