Regulation of CO<sub>2</sub> emissions from temperate streams and reservoirs
It has become more and more evident that CO<sub>2</sub> emission (<i>F</i><sub>CO</sub><sub>2</sub>) from freshwater systems is an important part of the global carbon cycle. To date, only a few studies have addressed the different mechanisms that regul...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-11-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/10/7539/2013/bg-10-7539-2013.pdf |
| _version_ | 1811343326400479232 |
|---|---|
| author | S. Halbedel M. Koschorreck |
| author_facet | S. Halbedel M. Koschorreck |
| author_sort | S. Halbedel |
| collection | DOAJ |
| description | It has become more and more evident that CO<sub>2</sub> emission
(<i>F</i><sub>CO</sub><sub>2</sub>) from freshwater systems is an important part of the
global carbon cycle. To date, only a few studies have addressed the different
mechanisms that regulate <i>F</i><sub>CO</sub><sub>2</sub> in lotic and lentic systems. In
a comparative study we investigated how different biogeochemical and physical
factors can affect <i>F</i><sub>CO</sub><sub>2</sub> values in streams and reservoirs. We
examined the seasonal variability in CO<sub>2</sub> concentrations and emissions
from four streams and two pre-dams of a large drinking water reservoir
located in the same catchment, and compared them with environmental factors
that were measured concurrently. All the streams were generally
supersaturated with CO<sub>2</sub> throughout the year, while both reservoirs
functioned to a small degree as CO<sub>2</sub> sinks during summer stratification
and CO<sub>2</sub> sources after circulation had set in. <i>F</i><sub>CO</sub><sub>2</sub> from
streams ranged from 23 to 355 mmol m<sup>−2</sup> d<sup>−1</sup> and exceeded the
fluxes recorded for the reservoirs (−8.9 to
161.1 mmol m<sup>−2</sup> d<sup>−1</sup>). Both the generally high piston velocity
(<i>k</i>) and the CO<sub>2</sub> oversaturation contributed to the higher
<i>F</i><sub>CO</sub><sub>2</sub> from streams in comparison to lakes. In both streams and
reservoirs <i>F</i><sub>CO</sub><sub>2</sub> was mainly governed by the CO<sub>2</sub>
concentration (<i>r</i> = 0.92, <i>p</i> < 0.001 for dams; <i>r</i> = 0.90, <i>p</i> < 0.001 for
streams), which was in turn affected by metabolic processes and nutrients in
both systems and also by lateral inflow in the streams. Besides CO<sub>2</sub>
concentration, physical factors also influence <i>F</i><sub>CO</sub><sub>2</sub> in lakes
and streams. During stratification, <i>F</i><sub>CO</sub><sub>2</sub> in both pre-dams was
regulated by primary production in the epilimnion, which led to a decrease of
<i>F</i><sub>CO</sub><sub>2</sub>. During circulation, when CO<sub>2</sub> from the hypolimnion
was mixed with the epilimnion, <i>F</i><sub>CO</sub><sub>2</sub> increased on account of
the CO<sub>2</sub> input from the hypolimnion. The CO<sub>2</sub> from the hypolimnion
originates from the mineralisation of organic matter. <i>F</i><sub>CO</sub><sub>2</sub>
from streams was mainly influenced by geomorphological and hydrological
factors affecting <i>k</i>, which is less relevant in low-wind lakes. Under
high-wind conditions, however, <i>k</i> regulates <i>F</i><sub>CO</sub><sub>2</sub> from lotic
systems as well. We developed a theoretical framework describing the role of
the different regulation mechanisms for <i>F</i><sub>CO</sub><sub>2</sub> from streams and
lakes.
<br><br>
In summary, the dominant factor affecting <i>F</i><sub>CO</sub><sub>2</sub> is the
concentration of CO<sub>2</sub> in the surface water. Lake stratification has a
very important regulatory effect on <i>F</i><sub>CO</sub><sub>2</sub> from lakes on account
of its influence on CO<sub>2</sub> concentrations and metabolic processes.
Nevertheless, <i>F</i><sub>CO</sub><sub>2</sub> values in heterotrophic streams are
generally higher. The higher <i>k</i> values are responsible for the comparatively
high degree of <i>F</i><sub>CO</sub><sub>2</sub>. On a Central European scale, CO<sub>2</sub>
emission from streams is probably of greater importance than the CO<sub>2</sub>
flux from standing waters. |
| first_indexed | 2024-04-13T19:27:24Z |
| format | Article |
| id | doaj.art-f6aeb3af73d24d868cea5ecf6ac58a4c |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-04-13T19:27:24Z |
| publishDate | 2013-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-f6aeb3af73d24d868cea5ecf6ac58a4c2022-12-22T02:33:21ZengCopernicus PublicationsBiogeosciences1726-41701726-41892013-11-0110117539755110.5194/bg-10-7539-2013Regulation of CO<sub>2</sub> emissions from temperate streams and reservoirsS. Halbedel0M. Koschorreck1Department Lake Research, Helmholtz Centre for Environmental Research – UFZ, Brückstrasse 3a, 39114 Magdeburg, GermanyDepartment Lake Research, Helmholtz Centre for Environmental Research – UFZ, Brückstrasse 3a, 39114 Magdeburg, GermanyIt has become more and more evident that CO<sub>2</sub> emission (<i>F</i><sub>CO</sub><sub>2</sub>) from freshwater systems is an important part of the global carbon cycle. To date, only a few studies have addressed the different mechanisms that regulate <i>F</i><sub>CO</sub><sub>2</sub> in lotic and lentic systems. In a comparative study we investigated how different biogeochemical and physical factors can affect <i>F</i><sub>CO</sub><sub>2</sub> values in streams and reservoirs. We examined the seasonal variability in CO<sub>2</sub> concentrations and emissions from four streams and two pre-dams of a large drinking water reservoir located in the same catchment, and compared them with environmental factors that were measured concurrently. All the streams were generally supersaturated with CO<sub>2</sub> throughout the year, while both reservoirs functioned to a small degree as CO<sub>2</sub> sinks during summer stratification and CO<sub>2</sub> sources after circulation had set in. <i>F</i><sub>CO</sub><sub>2</sub> from streams ranged from 23 to 355 mmol m<sup>−2</sup> d<sup>−1</sup> and exceeded the fluxes recorded for the reservoirs (−8.9 to 161.1 mmol m<sup>−2</sup> d<sup>−1</sup>). Both the generally high piston velocity (<i>k</i>) and the CO<sub>2</sub> oversaturation contributed to the higher <i>F</i><sub>CO</sub><sub>2</sub> from streams in comparison to lakes. In both streams and reservoirs <i>F</i><sub>CO</sub><sub>2</sub> was mainly governed by the CO<sub>2</sub> concentration (<i>r</i> = 0.92, <i>p</i> < 0.001 for dams; <i>r</i> = 0.90, <i>p</i> < 0.001 for streams), which was in turn affected by metabolic processes and nutrients in both systems and also by lateral inflow in the streams. Besides CO<sub>2</sub> concentration, physical factors also influence <i>F</i><sub>CO</sub><sub>2</sub> in lakes and streams. During stratification, <i>F</i><sub>CO</sub><sub>2</sub> in both pre-dams was regulated by primary production in the epilimnion, which led to a decrease of <i>F</i><sub>CO</sub><sub>2</sub>. During circulation, when CO<sub>2</sub> from the hypolimnion was mixed with the epilimnion, <i>F</i><sub>CO</sub><sub>2</sub> increased on account of the CO<sub>2</sub> input from the hypolimnion. The CO<sub>2</sub> from the hypolimnion originates from the mineralisation of organic matter. <i>F</i><sub>CO</sub><sub>2</sub> from streams was mainly influenced by geomorphological and hydrological factors affecting <i>k</i>, which is less relevant in low-wind lakes. Under high-wind conditions, however, <i>k</i> regulates <i>F</i><sub>CO</sub><sub>2</sub> from lotic systems as well. We developed a theoretical framework describing the role of the different regulation mechanisms for <i>F</i><sub>CO</sub><sub>2</sub> from streams and lakes. <br><br> In summary, the dominant factor affecting <i>F</i><sub>CO</sub><sub>2</sub> is the concentration of CO<sub>2</sub> in the surface water. Lake stratification has a very important regulatory effect on <i>F</i><sub>CO</sub><sub>2</sub> from lakes on account of its influence on CO<sub>2</sub> concentrations and metabolic processes. Nevertheless, <i>F</i><sub>CO</sub><sub>2</sub> values in heterotrophic streams are generally higher. The higher <i>k</i> values are responsible for the comparatively high degree of <i>F</i><sub>CO</sub><sub>2</sub>. On a Central European scale, CO<sub>2</sub> emission from streams is probably of greater importance than the CO<sub>2</sub> flux from standing waters.http://www.biogeosciences.net/10/7539/2013/bg-10-7539-2013.pdf |
| spellingShingle | S. Halbedel M. Koschorreck Regulation of CO<sub>2</sub> emissions from temperate streams and reservoirs Biogeosciences |
| title | Regulation of CO<sub>2</sub> emissions from temperate streams and reservoirs |
| title_full | Regulation of CO<sub>2</sub> emissions from temperate streams and reservoirs |
| title_fullStr | Regulation of CO<sub>2</sub> emissions from temperate streams and reservoirs |
| title_full_unstemmed | Regulation of CO<sub>2</sub> emissions from temperate streams and reservoirs |
| title_short | Regulation of CO<sub>2</sub> emissions from temperate streams and reservoirs |
| title_sort | regulation of co sub 2 sub emissions from temperate streams and reservoirs |
| url | http://www.biogeosciences.net/10/7539/2013/bg-10-7539-2013.pdf |
| work_keys_str_mv | AT shalbedel regulationofcosub2subemissionsfromtemperatestreamsandreservoirs AT mkoschorreck regulationofcosub2subemissionsfromtemperatestreamsandreservoirs |