title: Resource niche overlap promotes stability of bacterial community metabolism in experimental microcosms.
abstract: Decomposition of organic matter is an important ecosystem process governed in part by bacteria. The process of decomposition is expected to benefit from interspecific bacterial interactions such as resource partitioning and facilitation. However, the relative importance of resource niche breadth (metabolic diversity) and resource niche overlap (functional redundancy) on decomposition and the temporal stability of ecosystem processes received little scientific attention. Therefore, this study aims to evaluate the effect of an increase in bacterial community resemblance on both decomposition and the stability of bacterial metabolism in aquatic sediments. To this end, we performed laboratory microcosm experiments in which we examined the influence of bacterial consortia differing in number and composition of species on bacterial activity (Electron Transport System Activity, ETSA), dissolved organic carbon production and wavelet transformed measurements of redox potential (Eh). Single substrate affinities of the individual bacterial species were determined in order to calculate the metabolic diversity of the microbial community. Results presented here indicate that bacterial activity and organic matter decomposition increase with widening of the resource niche breadth, and that metabolic stability increases with increasing overlap in bacterial resource niches, hinting that resource niche overlap can promote the stability of bacterial community metabolism.
authors.affiliation: Department of Conservation Biology, Institute of Environmental Sciences (CML), Leiden University Leiden, Netherlands.
authors.forename: Ellard R
authors.initials: ER
authors.lastname: Hunting
authors.affiliation: Department of Conservation Biology, Institute of Environmental Sciences (CML), Leiden University Leiden, Netherlands.
authors.forename: Martina G
authors.initials: MG
authors.lastname: Vijver
authors.affiliation: Department of Aquatic Ecology and Ecotoxicology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, Netherlands.
authors.forename: Harm G
authors.initials: HG
authors.lastname: van der Geest
authors.affiliation: National Institute for Public Health and the Environment (RIVM-LER) - Centre for Sustainability, Environment and Health Bilthoven, Netherlands.
authors.forename: Christian
authors.initials: C
authors.lastname: Mulder
authors.affiliation: Department of Aquatic Ecology and Ecotoxicology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, Netherlands.
authors.forename: Michiel H S
authors.initials: MH
authors.lastname: Kraak
authors.affiliation: National Institute for Public Health and the Environment (RIVM-LER) - Centre for Sustainability, Environment and Health Bilthoven, Netherlands ; Department of Environmental Science, Institute for Water and Wetland Research, Radboud University Nijmegen, Netherlands.
authors.forename: Anton M
authors.initials: AM
authors.lastname: Breure
authors.affiliation: Department of Aquatic Ecology and Ecotoxicology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: Admiraal
keywords: decomposition; functional redundancy; niche complementarity; niche overlap; redox potential; wavelet transform