Isotopic and Elemental Variations of Carbon and Nitrogen in a Mangrove Estuary

Geochemistry of organic carbon and nitrogen in surface sediments of coastal Bohai Bay inferred from their ratios and stable isotopic signatures

“…Nitrogen isotopic compositions could be easily modified by a series of complex biogeochemical processes on some time scales. Dynamic cycling of nitrogen is subject to kinetic isotope fraction effects especially during the biogenic transformation and recycling of dissolved and particulate nitrogen compounds (Cifuentes et al, 1988(Cifuentes et al, , 1996Wu et al, 2003). Liu et al (2006) reported that heavier d…”

A geochemical record of environmental changes in sediments from Sishili Bay, northern Yellow Sea, China: Anthropogenic influence on organic matter sources and composition over the last 100years

“…5-7), respectively, and significant correlations between TOC and TN were found in the three cores (P < 0.01) ( Table 2). Based on previous studies (Meyers, 1994;Cifuentes et al, 1996), the organic matter sources of the three sites in our study seemed to be a mixture of marine and terrestrial sources with phytoplankton as the dominant component. However, considering the effects of oxidation and denitrification during sedimentation (Andrews et al, 1998;Waterson, 2005;Kuwae et al, 2006), the organic sources based on the TOC:TN values must be considered with caution, and there is a need to refer the ranges of d 13 C.…”

“…The TOC:TN ratio is an important indicator of the origin of organic matter, as there are obvious differences between different organic matter sources. For example, phytoplankton is usually approximately 6.7-10.1, bacteria ranges from 2.6 to 4.3, and high terrestrial vegetation is generally greater than 15 (Meyers, 1994;Cifuentes et al, 1996). However, organic matter breakdown (mineralization) can reduce the carbon and nutrient concentrations in the sediment.…”

Spatiotemporal Variation in Particulate Organic Carbon Based on Long-Term MODIS Observations in Taihu Lake, China

“…The POC/Chl-a is in the range of fresh phytoplankton ranges, between 33 and 100 [66]; this is much higher than that of sub-Antarctic water (50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60) [67], Great Wall Cove and Ardley Cove (74.62 ± 27.97) [65] and the East China Sea (64) [68]. However, it is much lower than that of dystrophic water (250-2500) [69], the Pacific Ocean (178 ± 30) [70], the Atlantic Ocean (253) and other ocean subsystems ( Table 2 in Fabiano et al [71]; Arrigo et al [72]; Table1 in Hadjimitsis et al [73]). The effect of atmospheric correction on the POC algorithm also should be considered in addition to the dominant water constituents of POC.…”