Large-scale controls on potential respiration and denitrification in riverine floodplains

Welti, Nina, Bondar-Kunze, Elisabeth, Singer, Gabriel, Tritthart, Michael., Zechmeister-Boltenstern, Sophie, Hein, Thomas and Pinay, Gilles (2012) Large-scale controls on potential respiration and denitrification in riverine floodplains. Ecological Engineering, 42 73-84. doi:10.1016/j.ecoleng.2012.02.005

Author Welti, Nina
Bondar-Kunze, Elisabeth
Singer, Gabriel
Tritthart, Michael.
Zechmeister-Boltenstern, Sophie
Hein, Thomas
Pinay, Gilles
Title Large-scale controls on potential respiration and denitrification in riverine floodplains
Journal name Ecological Engineering   Check publisher's open access policy
ISSN 0925-8574
Publication date 2012-01-01
Year available 2012
Sub-type Article (original research)
DOI 10.1016/j.ecoleng.2012.02.005
Open Access Status Not yet assessed
Volume 42
Start page 73
End page 84
Total pages 12
Place of publication Amsterdam, The Netherlands
Publisher Elsevier BV
Language eng
Subject 2305 Environmental Engineering
2308 Management, Monitoring, Policy and Law
2309 Nature and Landscape Conservation
Abstract Restoration measures of deteriorated river ecosystems generally aim at increasing the spatial heterogeneity and connectivity of these systems in order to increase biodiversity and ecosystem stability. While this is believed to benefit overall ecological integrity, consequences of such restoration projects on biogeochemical processes per se (i.e. ecosystem functioning) in fluvial systems are rarely considered. We address these issues by evaluating the characteristics of surface water connection between side arms and the main river channel in a former braided river section and the role and degree of connectivity (i.e. duration of surface water connection) on the sediment biogeochemistry. We hypothesized that potential respiration and denitrification would be controlled by the degree of hydrological connectivity, which was increased after floodplain restoration. We measured potential microbial respiration (SIR) and denitrification (DEA) and compared a degraded floodplain section of the Danube River with a reconnected and restored floodplain in the same river section. Re-establishing surface water connection altered the controls on sediment microbial respiration and denitrification ultimately impacting potential microbial activities. Meta-variables were created to characterize the effects of hydrology, morphology, and the available carbon and nutrient pools on potential microbial processing. Mantel statistics and path analysis were performed and demonstrate a hierarchy where the effects of hydrology on the available substrates and microbial processing are mediated by the morphology of the floodplain. In addition, these processes are highest in the least connected sites. Surface water connection, mediated by morphology regulates the potential denitrification rate and the ratio of N 2O to N 2 emissions, demonstrating the effects of restoration in floodplain systems.
Keyword Connectivity
Danube River
Denitrification enzyme activity
Floodplain restoration
Path analysis
Substrate induced respiration
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Civil Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 27 times in Thomson Reuters Web of Science Article | Citations
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Created: Tue, 21 Jan 2014, 00:57:15 EST by Julie Hunter on behalf of School of Civil Engineering