@article {2869,
	title = {Radiocarbon age of different photoreactive fractions of freshwater dissolved organic matter},
	journal = {Organic Geochemistry},
	volume = {135},
	year = {2019},
	month = {Jan-09-2019},
	pages = {11 - 15},
	abstract = {Dissolved organic carbon (DOC) plays a major role in aquatic carbon cycling. In order to determine if DOC photolability was related to DOC age, we tested the effect of oxidation time using UV irradiation on natural radiocarbon concentrations (Δ14C) of DOC in six US rivers. The most photo-labile DOC was 14C youngest. After a 100 min UV irradiation, most DOC (>93\%) was oxidized in two out of the six rivers studied. On the other hand, the other four rivers still had a considerable amount (>20\%) of DOC resistant to UV oxidation, which showed lower Δ14C values than those of bulk DOC. We also found that the concentration and Δ14C value of bulk DOC are controlled by the photochemically intermediate fraction. The results suggest that 14C age of organic matter is not homogeneous within DOC, the degree of which may depend on the characteristics unique to rivers.},
	keywords = {dissolved organic carbon, Mixing model, Oxidation time, UV irradiation, Δ14C},
	issn = {01466380},
	doi = {10.1016/j.orggeochem.2019.06.006},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S014663801930107X},
	author = {Ishikawa, Naoto F. and Butman, David and Raymond, Peter A.}
}
@article {2754,
	title = {Organic matter sources and lateral sedimentation in a Bahamian karst basin (sinkhole) over the late Holocene: Influence of local vegetation and climate},
	journal = {Palaeogeography, Palaeoclimatology, Palaeoecology},
	volume = {506},
	year = {2018},
	month = {Jan-10-2018},
	pages = {70 - 83},
	abstract = {Karst basins (e.g., blueholes, sinkholes) accumulate well-preserved sedimentary successions that provide transformative paleoclimatic and paleoenvironmental information. However, the sedimentary processes within these basins are not yet fully understood. Here we present stable carbon isotopic values (δ13Corg) and C:N ratios of bulk organic matter in well-dated sediment cores from Blackwood Sinkhole (Abaco, The Bahamas) to investigate the changing flux of organic matter into the sinkhole during the late Holocene. The provenance of preserved organic matter changed through the late Holocene between three primary sources, as determined by three-endmember mixing modeling: wetland organic matter from the adjacent epikarst surface, authigenic primary productivity in the oligohaline meteoric lens, and terrestrial organic matter from the surrounding landscape. Expansion of wetlands on the adjacent epikarst surface played a critical role by increasing the flux of wetland organic matter to the sinkhole, especially during the last 1000 years. Hurricanes and regional rainfall may have mediated organic matter delivery to the benthos, either through hampering wetland development (prior to 1000 cal yr BP) or by changing dissolved nutrient concentrations available in the basin for primary producers. These results demonstrate that organic matter provenance in karst basins is not constant through time, and is significantly dependent upon both landscape vegetation on the epikarst surface and changing hydrographic conditions that impacts nutrient availability to primary producers.},
	keywords = {Caribbean, Karst, Mixing model, Stable isotopes, Subtropical landscape},
	issn = {00310182},
	doi = {10.1016/j.palaeo.2018.06.014},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0031018218300683},
	author = {Tamalavage, Anne E. and van Hengstum, Peter J. and Louchouarn, Patrick and Molodtsov, Sergey and Kaiser, Karl and Donnelly, Jeffrey P. and Albury, Nancy A. and Fall, Patricia L.}
}
