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Influence of macroinvertebrates on physico-chemical and microbial processes in hyporheic sediments

Mermillod-Blondin, Florian and Gaudet, Jean-Paul and Gérino, Magali and Desrosiers, Gaston and Creuzé des Châtelliers, Michel Influence of macroinvertebrates on physico-chemical and microbial processes in hyporheic sediments. (2002) Hydrological Processes, 17 (4). 779-794. ISSN 0885-6087

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Official URL: http://dx.doi.org/10.1002/hyp.1165

Abstract

The objective of this study was to measure the effects of invertebrates on the physical characteristics and microbial processes in hyporheic sediments. We investigated the impacts of an assemblage of three taxa (asellids, chironomid larvae, and tubificid worms) on sediment distribution, water fluxes, sediment organic carbon, biofilm (attached bacteria) characteristics, and O2, dissolved organic carbon NO3−, NO2−, and NH4+ concentrations in slow filtration sand–gravel columns. The results showed that invertebrates clearly modified the distribution of particles in the sediment column, probably because of the structures (tubes, macropores, and faecal pellets) produced by the three taxa in the sediment. Our assessment of water fluxes indicated that invertebrate activities led to an increase in the porosity of the sediment columns. In addition, aerobic (O2 consumption) and anaerobic (denitrification and fermentative decomposition of organic matter) microbial processes occurring in the sediment were stimulated in the presence of invertebrates. Finally, the present study demonstrates that invertebrates can act as ecosystem engineers in heterogeneous sediments that are under the influence of an advective flux of water. The solute residence time increased in columns containing the faunal assemblage. Micro-organisms used more dissolved organic matter and nutrients in the presence of invertebrates because invertebrate activities increased the contact between the biofilm and water. We conclude that engineering by invertebrates in natural conditions modifies characteristics of the hyporheic zone and thereby enhances both the porosity of the sediment and the solute transport across the benthic interface.

Item Type:Article
Additional Information:Thanks to John Wiley and Sons editor. The definitive version is available at http://onlinelibrary.wiley.com/ The original PDF of the article can be found at Hydrological Processes website : http://onlinelibrary.wiley.com/doi/10.1002/hyp.1165/abstract
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Other partners > Institut polytechnique de Grenoble (FRANCE)
French research institutions > Institut de Recherche pour le Développement - IRD (FRANCE)
Other partners > Université de Paris Diderot - Paris 7 (FRANCE)
Other partners > Université Claude Bernard-Lyon I - UCBL (FRANCE)
Other partners > Ecole Pratique des Hautes Etudes - EPHE (FRANCE)
Other partners > Université Joseph Fourier Grenoble 1 - UJF (FRANCE)
Other partners > Université du Québec à Rimouski - UQAR (CANADA)
Laboratory name:
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Deposited By: Magali GERINO
Deposited On:04 Mar 2013 16:16

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