Major effects of alkalinity on the relationship between metabolism and dissolved inorganic carbon dynamics in lakes
Laen...
Kuupäev
2020
Kättesaadavus
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Springer
Abstrakt
Several findings suggest that CO 2 emissions in lakes
are not always directly linked to changes in metabolism but can be associated with interactions with
the dissolved inorganic carbon equilibrium. Alkalinity has been described as a determining factor in
regulating the relative contributions of biological
and inorganic processes to carbon dynamics in
lakes. Here we analyzed the relationship between
metabolic changes in dissolved oxygen (DO) and
dissolved inorganic carbon (DIC) at different timescales in eight lakes covering a wide range in
alkalinity. We used high-frequency data from
automatic monitoring stations to explore the sensitivity of DIC to metabolic changes inferred from
oxygen. To overcome the problem of noisy data,
commonly found in high-frequency measurements
datasets, we used Singular Spectrum Analysis to
enhance the diel signal-to-noise ratio. Our results
suggest that in most of the studied lakes, a large
part of the measured variability in DO and DIC reflects non-metabolic processes. Furthermore, at
low alkalinity, DIC dynamics appear to be mostly
driven by aquatic metabolism, but this relationship
weakens with increasing alkalinity. The observed
deviations from the metabolic 1:1 stoichiometry
between DO and DIC were strongly correlated with
the deviations expected to occur from calcite precipitation, with a stronger correlation when
accounting also for the benthic contribution of
calcite precipitation. This highlights the role of
calcite precipitation as an important driver of CO 2
supersaturation in lakes with alkalinity above
1 meq L-1 , which represents 57% of the global
area of lakes and reservoirs around the world.
This study was funded by MANTEL ITN (Management of climatic extreme events in lakes and reservoirs for the protection of ecosystem services) through European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No 722518, by Estonian Ministry of Education and Research (IUT 21-02), by the Estonian Research Council grant (PUT PSG32) and by the project C-HYDRO- CHANGE (CGL2017-86788-C3-3-P and CGL2017- 86788-C3-2-P) funded by the Spanish Ministry of Science, Innovation and Universities.
This study was funded by MANTEL ITN (Management of climatic extreme events in lakes and reservoirs for the protection of ecosystem services) through European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No 722518, by Estonian Ministry of Education and Research (IUT 21-02), by the Estonian Research Council grant (PUT PSG32) and by the project C-HYDRO- CHANGE (CGL2017-86788-C3-3-P and CGL2017- 86788-C3-2-P) funded by the Spanish Ministry of Science, Innovation and Universities.
Kirjeldus
Märksõnad
carbon dynamics, calcite precipitation, metabolism, alkalinity, dissolved inorganic carbon, high-frequency measurements, singular spectrum analysis, cross-wavelets analysis, articles