title: Resource Partitioning between Bacteria, Fungi, and Protists in the Detritusphere of an Agricultural Soil.
abstract: The flow of plant-derived carbon in soil is a key component of global carbon cycling. Conceptual models of trophic carbon fluxes in soil have assumed separate bacterial and fungal energy channels in the detritusphere, controlled by both substrate complexity and recalcitrance. However, detailed understanding of the key populations involved and niche-partitioning between them is limited. Here, a microcosm experiment was performed to trace the flow of detritusphere C from substrate analogs (glucose, cellulose) and plant biomass amendments (maize leaves, roots) in an agricultural soil. Carbon flow was traced by rRNA stable isotope probing and amplicon sequencing across three microbial kingdoms. Distinct lineages within theActinobacteria, Bacteroidetes, Gammaproteobacteria, Basidiomycota, Ascomycotaas well asPeronosporomyceteswere identified as important primary substrate consumers. A dynamic succession of primary consumers was observed especially in the cellulose treatments, but also in plant amendments over time. While intra-kingdom niche partitioning was clearly observed, distinct bacterial and fungal energy channels were not apparent. Furthermore, while the diversity of primary substrate consumers did not notably increase with substrate complexity, consumer succession and secondary trophic links to bacterivorous and fungivorous microbes resulted in increased food web complexity in the more recalcitrant substrates. This suggests that rather than substrate-defined energy channels, consumer succession as well as intra- and inter-kingdom cross-feeding should be considered as mechanisms supporting food web complexity in the detritusphere.
authors.affiliation: Institute of Soil Science and Land Evaluation, University of Hohenheim Stuttgart, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Kramer
authors.affiliation: Institute of Groundwater Ecology, Helmholtz Zentrum München - German Research Center for Environmental Health Neuherberg, Germany.
authors.forename: Dörte
authors.initials: D
authors.lastname: Dibbern
authors.affiliation: Department of Soil Ecology, Helmholtz Centre for Environmental Research Leipzig-HalleHalle, Germany; Institute of Biology, University of LeipzigLeipzig, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Moll
authors.affiliation: Department of Terrestrial Ecology, Institute of Zoology, University of Cologne Köln, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Huenninghaus
authors.affiliation: Department of Terrestrial Ecology, Institute of Zoology, University of Cologne Köln, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Koller
authors.affiliation: Department of Soil Ecology, Helmholtz Centre for Environmental Research Leipzig-Halle Halle, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Krueger
authors.affiliation: Institute of Soil Science and Land Evaluation, University of Hohenheim Stuttgart, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Marhan
authors.affiliation: Department of Bacterial Physiology, Institute for Microbiology, Ernst-Moritz-Arndt University of Greifswald Greifswald, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Urich
authors.affiliation: Department of Soil Ecology, Helmholtz Centre for Environmental Research Leipzig-HalleHalle, Germany; German Centre for Integrative Biodiversity Research (iDiv)Leipzig, Germany.
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Wubet
authors.affiliation: Department of Terrestrial Ecology, Institute of Zoology, University of Cologne Köln, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Bonkowski
authors.affiliation: Department of Soil Ecology, Helmholtz Centre for Environmental Research Leipzig-HalleHalle, Germany; Institute of Biology, University of LeipzigLeipzig, Germany; German Centre for Integrative Biodiversity Research (iDiv)Leipzig, Germany.
authors.forename: François
authors.initials: F
authors.lastname: Buscot
authors.affiliation: Institute of Groundwater Ecology, Helmholtz Zentrum München - German Research Center for Environmental Health Neuherberg, Germany.
authors.forename: Tillmann
authors.initials: T
authors.lastname: Lueders
authors.affiliation: Institute of Soil Science and Land Evaluation, University of Hohenheim Stuttgart, Germany.
authors.forename: Ellen
authors.initials: E
authors.lastname: Kandeler
keywords: amplicon sequencing; energy channels; plant litter decomposition; rRNA-SIP; stable isotope probing