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Unraveling the Unseen Players in the Ocean - A Field Guide to Water Chemistry and Marine Microbiology
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Water level changes affect carbon turnover and microbial community composition in lake sediments.
Lukas Weise1, Andreas Ulrich1, Matilde Moreano1
1Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg, Institute for Landscape Biogeochemistry, Eberswalderstr. 84, 15374 Müncheberg, Germany.
FEMS Microbiology Ecology
|February 24, 2016
Summary
Climate change will alter lake hydrology, impacting carbon cycling. Our study shows hydrological shifts increase allochthonous carbon uptake and CO2 emissions from lake sediments.
Area of Science:
- Environmental Science
- Microbiology
- Limnology
Background:
- Climate change is increasing hydrological variability in European lake littoral zones.
- Altered hydrological regimes can impact the utilization of allochthonous (external) and autochthonous (internal) carbon sources by microbes.
- Understanding these impacts is crucial for predicting carbon cycling in lake ecosystems.
Purpose of the Study:
- To investigate the effects of varying hydrological regimes (wet, desiccating, wet-desiccation cycles) on carbon turnover in sandy lake sediments.
- To quantify carbon uptake into bacterial biomass and respiration using (13)C-labelled organic carbon.
- To monitor microbial community composition and activity in response to hydrological changes.
Main Methods:
- Utilized sandy sediment microcosms subjected to controlled hydrological regimes.
- Employed (13)C-labelled particulate organic carbon to trace carbon flow into bacterial biomass (phospholipid fatty acids) and respiration.
- Assessed microbial community structure and dynamics using DNA/RNA-based real-time PCR and 16S rRNA T-RFLP analysis.
Main Results:
- Shifting hydrological regimes altered microbial organic carbon utilization and community composition.
- Drying sediments exhibited the highest carbon dioxide (CO2) emission rates.
- Hydrological shifts promoted the uptake of allochthonous organic carbon for respiration.
- Only extreme hydrological changes significantly altered active and total bacterial communities.
Conclusions:
- Hydrological variability in lake littoral zones, driven by climate change, influences microbial carbon cycling.
- Increased drought events and hydrological fluctuations are expected to enhance allochthonous carbon uptake and CO2 emissions.
- These changes have significant implications for the carbon budget and functioning of lake ecosystems.
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