Environmental control on microbial turnover of leaf carbon in streams

  • In aquatic ecosystems, light availability can significantly influence microbial turnover of terrestrial organic matter through associated metabolic interactions between phototrophic and heterotrophic communities. However, particularly in streams, microbial functions vary significantly with the structure of the streambed, that is the distribution and spatial arrangement of sediment grains in the streambed. It is therefore essential to elucidate how environmental factors synergistically define the microbial turnover of terrestrial organic matter in order to better understand the ecological role of photo-heterotrophic interactions in stream ecosystem processes. In outdoor experimental streams, we examined how the structure of streambeds modifies the influence of light availability on microbial turnover of leaf carbon (C). Furthermore, we investigated whether the studied relationships of microbial leaf C turnover to environmental conditions are affected by flow intermittency commonly occurring in streams. We applied leaves enriched with aIn aquatic ecosystems, light availability can significantly influence microbial turnover of terrestrial organic matter through associated metabolic interactions between phototrophic and heterotrophic communities. However, particularly in streams, microbial functions vary significantly with the structure of the streambed, that is the distribution and spatial arrangement of sediment grains in the streambed. It is therefore essential to elucidate how environmental factors synergistically define the microbial turnover of terrestrial organic matter in order to better understand the ecological role of photo-heterotrophic interactions in stream ecosystem processes. In outdoor experimental streams, we examined how the structure of streambeds modifies the influence of light availability on microbial turnover of leaf carbon (C). Furthermore, we investigated whether the studied relationships of microbial leaf C turnover to environmental conditions are affected by flow intermittency commonly occurring in streams. We applied leaves enriched with a 13C-stable isotope tracer and combined quantitative and isotope analyses. We thereby elucidated whether treatment induced changes in C turnover were associated with altered use of leaf C within the microbial food web. Moreover, isotope analyses were combined with measurements of microbial community composition to determine whether changes in community function were associated with a change in community composition. In this study, we present evidence, that environmental factors interactively determine how phototrophs and heterotrophs contribute to leaf C turnover. Light availability promoted the utilization of leaf C within the microbial food web, which was likely associated with a promoted availability of highly bioavailable metabolites of phototrophic origin. However, our results additionally confirm that the structure of the streambed modifies light-related changes in microbial C turnover. From our observations, we conclude that the streambed structure influences the strength of photo-heterotrophic interactions by defining the spatial availability of algal metabolites in the streambed and the composition of microbial communities. Collectively, our multifactorial approach provides valuable insights into environmental controls on the functioning of stream ecosystems.show moreshow less

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Metadaten
Author:Jenny Fabian, Sanja Zlatanović, Michael Mutz, Hans-Peter GrossartORCiDGND, Robert van Geldern, Andreas Ulrich, Gerd Gleixner, Katrin Premke
URN:urn:nbn:de:kobv:517-opus4-426336
DOI:https://doi.org/10.25932/publishup-42633
ISSN:1866-8372
Parent Title (English):Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
Subtitle (English):ecological function of phototrophic-heterotrophic interactions
Series (Serial Number):Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe (693)
Document Type:Postprint
Language:English
Date of first Publication:2019/04/05
Year of Completion:2018
Publishing Institution:Universität Potsdam
Release Date:2019/04/05
Tag:13C stable isotopes; PLFA; algae; bacteria; light; microbial interactions; streambed structure; terrestrial carbon
Issue:693
Pagenumber:16
Source:Frontiers in Microbiology 9 (2018) Art. 1044 DOI: 10.3389/fmicb.2018.01044
Organizational units:Mathematisch-Naturwissenschaftliche Fakultät
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Peer Review:Referiert
Publication Way:Open Access
Grantor:Frontiers
Licence (German):License LogoCreative Commons - Namensnennung, 4.0 International