@article {2628,
	title = {Temporal deconvolution of vascular plant-derived fatty acids exported from terrestrial watersheds},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {244},
	year = {2019},
	month = {Jan-01-2019},
	pages = {502 - 521},
	abstract = {Relatively little is known about the amount of time that lapses between the photosynthetic fixation of carbon by vascular land plants and its incorporation into the marine sedimentary record, yet the dynamics of terrestrial carbon sequestration have important implications for the carbon cycle. Vascular plant carbon may encounter multiple potential intermediate storage pools and transport trajectories, and the age of vascular plant carbon accumulating in marine sediments will reflect these different pre-depositional histories. Here, we examine down-core C-14 profiles of higher plant leaf wax-derived fatty acids isolated from high fidelity sedimentary sequences spanning the so-called "bomb-spike", and encompassing a ca. 60-degree latitudinal gradient from tropical (Cariaco Basin), temperate (Saanich Inlet), and polar (Mackenzie Delta) watersheds to constrain integrated vascular plant carbon storage/transport times ("residence times").

Using a modeling framework, we find that, in addition to a "young" (conditionally defined as < 50 y) carbon pool, an old pool of compounds comprises 49 to 78 \% of the fractional contribution of organic carbon (OC) and exhibits variable ages reflective of the environmental setting. For the Mackenzie Delta sediments, we find a mean age of the old pool of 28 ky (+/- 9.4, standard deviation), indicating extensive pre-aging in permafrost soils, whereas the old pools in Saanich Inlet and Cariaco Basin sediments are younger, 7.9 (+/- 5.0) and 2.4 (+/- 0.50) to 3.2 (+/- 0.54) ky, respectively, indicating less protracted storage in terrestrial reservoirs. The "young" pool showed clear annual contributions for Saanich Inlet and Mackenzie Delta sediments (comprising 24\% and 16\% of this pool, respectively), likely reflecting episodic transport of OC from steep hillside slopes surrounding Saanich Inlet and annual spring flood deposition in the Mackenzie Delta, respectively. Contributions of 5-10 year old OC to the Cariaco Basin show a short delay of OC inflow, potentially related to transport time to the offshore basin. Modeling results also indicate that the Mackenzie Delta has an influx of young but decadal material (20-30 years of age), pointing to the presence of an intermediate reservoir.

Overall, these results show that a significant fraction of vascular plant C undergoes pre-aging in terrestrial reservoirs prior to accumulation in deltaic and marine sediments. The age distribution, reflecting both storage and transport times, likely depends on landscape-specific factors such as local topography, hydrographic characteristics, and mean annual temperature of the catchment, all of which affect the degree of soil buildup and preservation. We show that catchment-specific carbon residence times across landscapes can vary by an order of magnitude, with important implications both for carbon cycle studies and for the interpretation of molecular terrestrial paleoclimate records preserved in sedimentary sequences.},
	keywords = {british-columbia, CARIACO BASIN, compound-specific radiocarbon, MACKENZIE DELTA, marine-sediments, odp leg 169s, saanich inlet, SANTA-MONICA BASIN, SOIL ORGANIC-MATTER, TROPICAL VEGETATION},
	issn = {00167037},
	doi = {10.1016/j.gca.2018.09.034},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0016703718305702https://api.elsevier.com/content/article/PII:S0016703718305702?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0016703718305702?httpAccept=text/plain},
	author = {Vonk, Jorien E. and Drenzek, Nicholas J. and Hughen, Konrad A. and Stanley, Rachel H.R. and McIntyre, Cameron and {\c c}on, Daniel B. and Giosan, Liviu and Southon, John R. and Santos, Guaciara M. and Druffel, Ellen R.M. and Andersson, August A. and {\"o}ld, Martin and Eglinton, Timothy I.}
}
@article {2602,
	title = {Biological and physical controls on the flux and characteristics of sinking particles on the Northwest Atlantic margin},
	journal = {Journal of Geophysical Research: Oceans},
	volume = {122},
	year = {2017},
	month = {Jan-06-2017},
	pages = {4539 - 4553},
	abstract = {Biogenic matter characteristics and radiocarbon contents of organic carbon (OC) were examined on sinking particle samples intercepted at
three nominal depths of 1000 m, 2000 m, and 3000 m (similar to 50 m above the seafloor) during a 3 year sediment trap program on the New England slope in the Northwest Atlantic. We have sought to characterize the sources of sinking particles in the context of vertical export of biogenic particles from the overlying water column and lateral supply of resuspended sediment particles from adjacent margin sediments. High aluminum (Al) abundances and low OC radiocarbon contents indicated contributions from resuspended sediment which was greatest at 3000 m but also significant at shallower depths. The benthic source (i.e., laterally supplied resuspended sediment) of opal appears negligible based on the absence of a correlation with Al fluxes. In comparison, CaCO3 fluxes at 3000 m showed a positive correlation with Al fluxes. Benthic sources accounted for 42 similar to 63\% of the sinking particle flux based on radiocarbon mass balance and the relationship between Al flux and CaCO3 flux. Episodic pulses of Al at 3000 m were significantly correlated with the near-bottom current at a nearby hydrographic mooring site, implying the importance of current variability in lateral particle transport. However, Al fluxes at 1000 m and 2000 m were coherent but differed from those at 3000 m, implying more than one mode of lateral supply of particles in the water column.},
	doi = {10.1002/jgrc.v122.610.1002/2016JC012549},
	url = {http://doi.wiley.com/10.1002/jgrc.v122.6http://doi.wiley.com/10.1002/2016JC012549http://onlinelibrary.wiley.com/wol1/doi/10.1002/2016JC012549/fullpdfhttps://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002\%2F2016JC012549},
	author = {Hwang, Jeomshik and Manganini, Steven J. and Park, JongJin and {\c c}on, Daniel B. and Toole, John M. and Eglinton, Timothy I.}
}
