Controls and significance of priming effects in lake sediments
© 2023 John Wiley & Sons Ltd.
| Veröffentlicht in: | Global change biology. - 1999. - 30(2024), 1 vom: 26. Jan., Seite e17076 |
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| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
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| Zugriff auf das übergeordnete Werk: | Global change biology |
| Schlagworte: | Journal Article climate change eutrophication cyanobacteria lake carbon methanogenesis priming effects sediments stoichiometry Carbon 7440-44-0 |
| Zusammenfassung: | © 2023 John Wiley & Sons Ltd. Warming and eutrophication influence carbon (C) processing in sediments, with implications for the global greenhouse-gas budget. Temperature effects on sedimentary C loss are well understood, but the mechanism of change in turnover through priming with labile organic matter (OM) is not. Evaluating changes in the magnitude of priming as a function of warming, eutrophication, and OM stoichiometry, we incubated sediments with 13 C-labeled fresh organic matter (FOM, algal/cyanobacterial) and simulated future climate scenarios (+4°C and +8°C). We investigated FOM-induced production of CH4 and microbial community changes. C loss was primed by up to 17% in dominantly allochthonous sediments (ranging from 5% to 17%), compared to up to 6% in autochthonous sediments (-9% to 6%), suggesting that refractory OM is more susceptible to priming. The magnitude of priming was dependent on sediment OM stoichiometry (C/N ratio), the ratio of fresh labile OM to microbial biomass (FOM/MB), and temperature. Priming was strongest at 4°C when FOM/MB was below 50%. Addition of FOM was associated with activation and growth of bacterial decomposers, including for example, Firmicutes, Bacteroidetes, or Fibrobacteres, known for their potential to degrade insoluble and complex structural biopolymers. Using sedimentary C/N > 15 as a threshold, we show that in up to 35% of global lakes, sedimentation is dominated by allochthonous rather than autochthonous material. We then provide first-order estimates showing that, upon increase in phytoplankton biomass in these lakes, priming-enabled degradation of recalcitrant OM will release up to 2.1 Tg C annually, which would otherwise be buried for geological times |
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| Beschreibung: | Date Completed 29.01.2024 Date Revised 06.02.2024 published: Print Citation Status MEDLINE |
| ISSN: | 1365-2486 |
| DOI: | 10.1111/gcb.17076 |