scholarly journals Carbon and nitrogen isotope ratios in meteoritic organic matter: indicators of alteration processes on the parent asteroid

2004 ◽  
Vol 3 (3) ◽  
pp. 221-227 ◽  
Author(s):  
Mark A. Sephton ◽  
Alexander B. Verchovsky ◽  
Ian P. Wright
Keyword(s):  
Stable Isotopes ◽  
Organic Matter ◽  
Solar System ◽  
Thermal Processing ◽  
Organic Materials ◽  
Nitrogen Isotope ◽  
Nitrogen Stable Isotopes ◽  
Data Set ◽  
Carbon And Nitrogen ◽  
Alteration Processes

Macromolecular organic materials in chondrites display significant variations in carbon and nitrogen stable isotopes. In recent years, these variations have been interpreted as a record of aqueous and thermal processing on asteroids shortly after the birth of the Solar System. In this paper we review and summarize the key data and main interpretative approaches related to this study area. Armed with these methods we attempt to reinterpret the whole rock chondrite data set in the literature.

Predicting soil organic matter stability in agricultural fields through carbon and nitrogen stable isotopes

2015 ◽  
Vol 88 ◽  
pp. 29-38 ◽  
Author(s):  
Tim De Clercq ◽  
Maria Heiling ◽  
Gerd Dercon ◽  
Christian Resch ◽  
Martina Aigner ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Agricultural Fields ◽  
Nitrogen Stable Isotopes ◽  
Carbon And Nitrogen

Pathways of organic matter in an estuarine mangrove trophic network assessed by carbon and nitrogen stable isotopes

2017 ◽  
Vol 98 (7) ◽  
pp. 1559-1569
Author(s):  
Yves Letourneur ◽  
Marine J. Briand ◽  
Gaël Guillou
Keyword(s):  
Stable Isotopes ◽  
Organic Matter ◽  
Food Web ◽  
New Caledonia ◽  
Avicennia Marina ◽  
Trophic Levels ◽  
Nitrogen Stable Isotopes ◽  
Wet Season ◽  
Mangrove Species ◽  
Carbon And Nitrogen

Carbon and nitrogen stable isotopes were used to describe an estuarine mangrove food web in New Caledonia, SW Pacific. Isotopic values were measured for all components of the ecosystem, from various organic matter (OM) sources to predators. Primary producers showed δ13C values from −32.29‰ (Bruguiera gymnorhiza) to −24.67‰ (mouth particulate organic matter), whereas δ15N values ranged from 1.48‰ (Avicennia marina) to 10.17‰ (Eichomia crassipes). Two potential organic matter sources, i.e. the mangrove species and E. crassipes, appeared not to be directly used by consumers although were indirectly entering the food web through particulate and sedimentary organic matter pools (POM and SOM). Overall, invertebrates showed C-depleted and N-depleted values compared with fish, highlighting their lower trophic level. The highest trophic levels in this estuarine mangrove were represented by carangids (δ15N of 11.24‰ for Caranx sp. and 10.81‰ for Carangoides fulvoguttatus) and gerrids (δ15N of 10.42‰ for Gerres filamentosus). Two main pathways of organic matter were identified from sources of OM to end-members, i.e. from estuarine POM and SOM toward gerrids and from marine POM towards carangids. The food chain comprised three or four trophic levels, depending on the pathway of organic matter. The position of some consumer species within the reconstructed food web might imply that an important source of organic matter was probably missing, i.e. microphytobenthos. Despite an obvious connection, the role of river inputs as potential drivers of mangrove food web dynamics appeared important only during the wet season.

scholarly journals Assessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis

2006 ◽  
Vol 86 (6) ◽  
pp. 1443-1447 ◽  
Author(s):  
D. Fourgon ◽  
G. Lepoint ◽  
I. Eeckhaut
Keyword(s):  
Stable Isotopes ◽  
Potential Benefit ◽  
Feeding Habits ◽  
Isotope Analysis ◽  
Tracer Experiment ◽  
Trophic Relationships ◽  
Nitrogen Stable Isotopes ◽  
Carbon And Nitrogen ◽  
C And N ◽  
The One

Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiuroids, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess the potential benefit obtained by the symbiotic Ophiomastix venosa juveniles. A tracer experiment was also carried out to clarify the contribution of algae to the nitrogen uptake amongst the tested ophiuroids. Our results suggest that Ophiocoma scolopendrina adults occupy a higher position in the food web than Ophiomastix venosa and mainly feed on neuston. In contrast, O. venosa adults feed on the alga Sargassum densifolium and on organic matter associated with sediment. Free juveniles and symbiotic juveniles of O. venosa have intermediate δ13C values between both adult species. The high proportion of 13C in the symbiotic juveniles compared to the one in their conspecific adults indicates that their diet slightly differs from the latter and is closer to that of Ophiocoma scolopendrina. This raises the hypothesis that symbiotic juveniles steal neuston from their associated host, O. scolopendrina.

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