Temperature effect on respiration and photosynthesis of the symbiont-bearing planktonic foraminifera $Globigerinoides\ ruber$ , $Orbulina\ universa$ , and $Globigerinella\ siphonifera$
Respiration and photosynthesis of the planktonic foraminifera Globigerinoides ruber, Orbulina universa, andGlobigerinella siphonifera and their symbiotic algae were calculated from measured dissolved oxygen gradientsusing microelectrodes, using different temperatures in dark and light (250 mmol phot...
| Published in: | Limnology and Oceanography |
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| Main Authors: | , , , |
| Format: | Other/Unknown Material |
| Language: | English |
| Published: |
American Society of Limnology and Oceanography
2009
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| Subjects: | |
| Online Access: | https://oskar-bordeaux.fr/handle/20.500.12278/30046 https://doi.org/10.4319/lo.2009.54.1.0210 |
| Summary: | Respiration and photosynthesis of the planktonic foraminifera Globigerinoides ruber, Orbulina universa, andGlobigerinella siphonifera and their symbiotic algae were calculated from measured dissolved oxygen gradientsusing microelectrodes, using different temperatures in dark and light (250 mmol photon m$^{-2} s^{-12}$ conditions. Atone temperature (24°C) the respiration rate increased as a power function of the foraminiferan organic carbonmass with a 0.57 $\pm$ 0.18 exponent. The effect of temperature on respiration was quantified in two ways: bynormalizing the rates to the organic carbon mass and by normalizing the observed rates to a constant temperature(24°C). This latter normalization was also used for photosynthesis. The respiration rates increase as a function oftemperature for all species and can be described either with a $Q_{10}$ = 3.18 ($\pm$0.27) or with an Arrheniustemperature of $T_A$ = 10,293°K ($\pm$768°K). Similar calculations for net photosynthesis yielded a $Q_{10}$ 2.68($\pm$0.36) and a $T_A$ = 8766°K ($\pm$1203°K), and calculations for gross photosynthesis yielded a $Q_{10}$= 2.76 ($\pm$0.29) and a $T_A$ = 9026°K ($\pm$926°K). For the species studied, the photosynthesis : respiration ratio varied from moderate for $G.\ siphonifera$ (0.58) to very high (13) for $O.\ universa$. The high ratios indicate that photosynthesis is muchhigher than the carbon requirements for both foraminifera and symbiont growth. This excess carbon might be the source of organic exudates Quantification de la variabilité hydrologique naturelle et anthropique de l'Atlantique nord à partir des foraminifères fossiles |
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