Photosynthetic activity of Arctic Vaucheria (Xanthophyceae) measured in microcosmos
The xanthophycean alga Vaucheria inhabits very variable, and hence extreme, ecosys-tem of polar river estuaries. Therefore, it represents a unique system for the study of adaptation/acclimatization mechanisms. Since the ecophysiological measurements cannot be performed in the field directly, a piece...
| Published in: | Czech Polar Reports |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
Masaryk University Press
2017
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.5817/cpr2017-1-6 https://journals.muni.cz/CPR/article/viewFile/12906/11234 |
| Summary: | The xanthophycean alga Vaucheria inhabits very variable, and hence extreme, ecosys-tem of polar river estuaries. Therefore, it represents a unique system for the study of adaptation/acclimatization mechanisms. Since the ecophysiological measurements cannot be performed in the field directly, a piece of Vaucheria community collected in the Adventelva estuary, Longyearbyen, Svalbard, was taken to a microcosmos in order to study it. The set of instrumentation for measurement of ecophysiological parameters was constructed for such a field study. The community structure and photosynthetic activity expressed as the dissolved oxygen concentration and effective quantum yield (and hence relative electron transfer rate) were measured. The study defined relations between encountered environmental conditions and Vaucheria photosynthetic activity in late Arctic summer. The community consisted almost entirely of Vaucheria thalli; small marine pennate diatoms were rare. The microcosmos was proved functional since the structure of the community remained unaffected. Both methods of photosynthetic activity measurement were able to record its diel changes during 10 days lasting incubation. Although only weak correlation was found between the oxygen concentration and variable chlorophyll, probably due to the time necessary for oxygen diffusion, data from fluorometers were highly correlated. The Vaucheria expressed diel cycles in the photosynthetic activity, and the photosynthetically active radiation was the main driving factor. The incubation in microcosmos proved to be suitable for ecophysiological studies which will include the addition of tidal cycles and more sophisticated protocols for photosynthetic activity measurement. |
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