Estop-Aragonés, C; Knorr, KH; Blodau, C: Belowground in situ redox dynamics and methanogenesis recovery in a degraded fen during dry-wet cycles and flooding, Biogeosciences, 10, 421-436 (2013) [Link]
Abstract:
Climate change induced drying and flooding may alter the redox conditions of organic matter decomposition in peat soils. The seasonal and intermittent changes in pore water solutes (NO3−, Fe2+, SO42−, H2S, acetate) and dissolved soil gases (CO2, O2, CH4, H2) under natural water table fluctuations were compared to the response under a reinforced drying and flooding in fen peats. Oxygen penetration during dryings led to CO2 and CH4 degassing and to a regeneration of dissolved electron acceptors (NO3−, Fe3+ and SO42−). Drying intensity controlled the extent of the electron acceptor regeneration. Iron was rapidly reduced and sulfate pools ~ 1 mmol L−1 depleted upon rewetting and CH4 did not substantially accumulate until sulfate levels declined to ~ 100 μmoll−1. The post-rewetting recovery of soil methane concentrations to levels ~ 80 μmoll−1 needed 40–50 days after natural drought. This recovery was prolonged after experimentally reinforced drought. A greater regeneration of electron acceptors during drying was not related to prolonged methanogenesis suppression after rewetting. Peat compaction, solid phase content of reactive iron and total reduced inorganic sulfur and organic matter content controlled oxygen penetration, the regeneration of electron acceptors and the recovery of CH4 production, respectively. Methane production was maintained despite moderate water table decline of 20 cm in denser peats. Flooding led to accumulation of acetate and H2, promoted CH4 production and strengthened the co-occurrence of iron and sulfate reduction and methanogenesis. Mass balances during drying and flooding indicated that an important fraction of the electron flow must have been used for the generation and consumption of electron acceptors in the solid phase or other mechanisms. In contrast to flooding, dry-wet cycles negatively affect methane production on a seasonal scale but this impact might strongly depend on drying intensity and on the peat matrix, whose structure and physical properties influence moisture content.
Upcoming ...


BayCEER Colloquium:
Th. 2020-12-03
An engineered (water) future?
Th. 2020-12-10
Investigating communal pathogen defense and its role in social evolution
Ecological-Botanical Garden:
Th. 2020-12-03
Entfällt: Ökumenische Andacht zum Advent mit dem Swahili Chor Bayreuth (KHG & ESG)
Su. 2020-12-06
Entfällt: Führung nach Anmeldung: Zimt & Mandelkern: Pflanzen in der Weihnachtsbäckerei
Geographisches Kolloquium:
Tu. 2020-12-08
People, pathogens, places: where medical geography meets disease ecology?
BayCEER Blog
13.01.2020
Why Science Communication?
24.05.2019
Stoichiometric controls of C and N cycling
07.05.2019
Flying halfway across the globe to dig in the dirt – a research stay in Bloomington, USA
16.04.2019
Picky carnivorous plants?
RSS Blog as RSS Feed
Weather research site
Luftdruck (356m): 982.0 hPa
Lufttemperatur: -2.0 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 17m): 3.6 km/h
Wind (Max.): 5.4 km/h
Windrichtung: SW

...more
Globalstrahlung: -5 W/m²
Lufttemperatur: -2.6 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 32m): 0.0 km/h

...more
This site makes use of cookies More information