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Hydrologic linkages drive spatial structuring of bacterial assemblages and functioning in alpine floodplains
Remo Freimann1, Helmut Bürgmann2, Stuart E G Findlay3
1Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology ETH Zurich, Dübendorf, Switzerland ; Institute of Integrative Biology ETH Zurich, Zürich, Switzerland ; Department of Biology, Institute of Molecular Health Sciences, Epigenetic Regulation and Cell Identity Control ETH Zurich, Zürich, Switzerland.
Frontiers in Microbiology
|November 19, 2015
Summary
Hydrological connectivity significantly influences microbial functions in alpine floodplains, impacting enzymatic activities more than bacterial community structure. Understanding these flow-related mechanisms is crucial for ecosystem management.
Area of Science:
- Environmental Microbiology
- Ecology
- Hydrology
Background:
- Microbial communities and functions are shaped by habitat, dispersal, and interactions.
- Hydrological flow in groundwater systems introduces spatial structure and directional dependencies.
- Alpine floodplains present unique environments where hydrology can strongly influence microbial processes.
Purpose of the Study:
- To investigate the role of hydrology in structuring bacterial communities and their functions in alpine floodplains.
- To assess the impact of different hydrological states on microbial assemblages and enzymatic activities.
- To determine the relative importance of hydrologically-driven processes compared to other factors.
Main Methods:
- Installation of piezometers in stream sediments and riparian zones to monitor hydrological flows.
- Utilizing piezometers as incubation chambers to analyze bacterial community structure and enzymatic functions.
- Employing spatial eigenvector models and physico-chemical groundwater characteristic models to evaluate hydrological influences.
Main Results:
- Hydrological connectivity demonstrated a strong influence, explaining up to 40% of variation in enzymatic activities.
- The impact of hydrology on bacterial community structure was less pronounced, indicating functional plasticity or redundancy.
- Flow-related mechanisms were consistently the most significant factor in explaining both bacterial structure and functioning across different hydrological periods.
Conclusions:
- Hydrology plays a critical role in shaping microbial functions and community structure in alpine floodplain ecosystems.
- Ecosystem management strategies for floodplains should integrate an understanding of hydrological changes and their effects on microbial processes.
- Models predicting ecosystem functioning should incorporate hydrological connectivity to improve accuracy.
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