Is UV-B radiation affecting charophycean algae in shallow freshwater systems?
The objective of this study was to determine the effects of UV-B radiation on charophycean algae under natural conditions, since charophytes enhance water transparency in freshwater systems and levels of UV-B radiation have increased by ozone depletion. Potential and actual UV-B effects were studied...
| Published in: | New Phytologist |
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| Main Authors: | , , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2005
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| Subjects: | |
| Online Access: | https://research.vu.nl/en/publications/032cd602-bc1f-46e2-9504-0eb1969c4cf5 https://doi.org/10.1111/j.1469-8137.2005.01377.x |
| Summary: | The objective of this study was to determine the effects of UV-B radiation on charophycean algae under natural conditions, since charophytes enhance water transparency in freshwater systems and levels of UV-B radiation have increased by ozone depletion. Potential and actual UV-B effects were studied by combining a glasshouse experiment in which plants were exposed to various levels of UV-B radiation and field measurements in two freshwater systems dominated by charophytes in the Netherlands. The glasshouse experiment showed that charophytes were sensitive to UV-B radiation. UV-B radiation negatively affected growth, while it increased levels of DNA damage in Chara aspera. Moreover, the charophytes did not seem to develop UV-B screens to protect against UV-B radiation since no increase in UV-B absorbing compounds was found. At field conditions, both spectroradiometrical measurements and DNA dosimeters showed that UV-B radiation was attenuated quickly in both freshwater systems, indicating that UV-B does not reach the submerged charophyte vegetation. However, specific conditions, like fluctuating water tables, may result in UV-B exposure to charophytes for certain periods annually. © New Phytologist (2005). |
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