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Réponse des processus biochimiques d'une tourbière soumise à des fluctuations du niveau d'eau

Abstract : Wetlands are recognized to play an important role in regulating global biogeochemical cycles. Actually they serve as sinks, sources and transformers of nutrients. They are very sensitive to changes in hydrology that may be brought about by climate or anthropogenic pressures. The work presented here applies an interdisciplinary approach by combining hydrology, geophysics, hydrochemistry, biology and numerical modelisation. The investigated site is a peatland meadow located in Normandy, NW France. Groundwater dating enabled to gain knowledge on the aquifer conceptual functioning. The modelisation highlights the interactions between the wetland and the aquifer and predicts an important impact of groundwater extraction and climate change on the wetland water levels that may lead to desiccation and on the stream flows. The study confirms that peat biochemical vulnerability is highly dependant on the peat quality. A more degraded peat, i.e. with lower nutrient and biomass content, is more sensitive to oxidation processes, which results in important acidification and sulphate and cations leaching. Desiccation increases these processes and is clearly destructive. The results confirm that, while anaerobic conditions must be favoured in peatland management, regular small water table fluctuations do not disturb the peat functioning, as a nutrient transformer.
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Submitted on : Thursday, April 4, 2013 - 4:44:12 PM
Last modification on : Thursday, January 14, 2021 - 11:46:48 AM

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  • HAL Id : tel-00807995, version 1

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Jo de Ridder. Réponse des processus biochimiques d'une tourbière soumise à des fluctuations du niveau d'eau. Hydrologie. Université Rennes 1, 2012. Français. ⟨tel-00807995⟩

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