TY  - GEN
A1  - Fabian, Jenny
A1  - Zlatanović, Sanja
A1  - Mutz, Michael
A1  - Grossart, Hans-Peter
A1  - Geldern, Robert van
A1  - Ulrich, Andreas
A1  - Gleixner, Gerd
A1  - Premke, Katrin
T1  - Environmental control on microbial turnover of leaf carbon in streams
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - 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 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 693 
KW  - algae
KW  - bacteria
KW  - microbial interactions
KW  - 13C stable isotopes
KW  - PLFA
KW  - terrestrial carbon
KW  - streambed structure
KW  - light
Y1  - 2019
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/42633
UR  - https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-426336
SN  - 1866-8372
IS  - 693
ER  -