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Van Maldegem, Lennart M.; Sansjofre, Pierre; Weijers, Johan W. H.; Wolkenstein, Klaus; Strother, Paul K.; Woermer, Lars; Hefter, Jens; Nettersheim, Benjamin J.; Hoshino, Yosuke; Schouten, Stefan; Damste, Jaap S. Sinninghe; Nath, Nilamoni; Griesinger, Christian; Kuznetsov, Nikolay B.; Elie, Marcel; Elvert, Marcus; Tegelaar, Erik; Gleixner, Gerd; Hallmann, Christian. |
Eukaryotic algae rose to ecological relevance after the Neoproterozoic Snowball Earth glaciations, but the causes for this consequential evolutionary transition remain enigmatic. Cap carbonates were globally deposited directly after these glaciations, but they are usually organic barren or thermally overprinted. Here we show that uniquely-preserved cap dolostones of the Araras Group contain exceptional abundances of a newly identified biomarker: 25,28-bisnorgammacerane. Its secular occurrence, carbon isotope systematics and co-occurrence with other demethylated terpenoids suggest a mechanistic connection to extensive microbial degradation of ciliate-derived biomass in bacterially dominated ecosystems. Declining 25,28-bisnorgammacerane concentrations, and a... |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74951/76030.pdf |
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Ray, Raghab; Thouzeau, Gerard; Walcker, Romain; Vantrepotte, Vincent; Gleixner, Gerd; Morvan, Sylvain; Devesa, Jeremy; Michaud, Emma. |
There is growing evidence that a substantial fraction of the dissolved organic and inorganic carbon (DOC and DIC) and particulate organic carbon (POC) can be exported from mangroves to the ocean. Yet our understanding of C fluxes in mangrove forests is limited to only few regional studies that exclude the world's longest sediment dispersal system connected to the Amazon River. The present study aims at (1) examining tidal fluctuations of DOC, POC, and DIC; their isotopes; and optical properties such as chromophoric dissolved organic matter (CDOM) and (2) estimating their exchange fluxes between the mangroves and adjacent coastal water in the Sinnamary estuary, French Guiana. Time series observation highlighted that physical processes coupled to tides... |
Tipo: Text |
Palavras-chave: Organic matter; Tidal cycle; Carbon flux; Mangroves; French Guiana. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75488/76339.pdf |
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Thoms, Carolin; Gattinger, Andreas; Jacob, Mascha; Thomas, Frank M.; Gleixner, Gerd. |
We investigated the link between aboveground and belowground diversity in temperate deciduous forest ecosystems. To this end, we determined the effects of the tree species composition on the biomass and composition of the soil microbial community using phospholipid fatty acid (PLFA) profiles in the Hainich National Park, a deciduous mixed forest on loess over limestone in Central-Germany. We investigated the effects of the leaf litter composition on the microbial community, hypothesizing that distinctive leaf litter compositions increase signature PLFAs. In addition, we studied the impact of clay content, pH and nutrient status of the soil on the microbial community in different surface soil layers. Consequently, soil was sampled from depths of 0–5 cm,... |
Tipo: Journal paper |
Palavras-chave: Soil. |
Ano: 2010 |
URL: http://orgprints.org/26368/1/Thoms_etal_2010_SBB42.pdf |
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