ISSN:
1432-1793
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The ratio of variable fluorescence to maximal fluorescence (F v/F m) was measured during a night and day cycle in five different macroalgae growing in the littoral zone at the Swedish west coast; the green algae Ulva lactuca, Cladophora sp. and Enteromorpha flexousa, the red alga Ceramium nodulosum and the brown alga Fucus vesiculosus. All the green algae and C. nodulosum showed both diurnal fluctuations in F v/F m during days of high light intensities and a significant negative correlation between F v/F m and photon irradiance (PI). An attempt has been made to improve calculations of macroalgal net growth based on carbon fixation (αnet) considering this diurnal change in F v/F m. By assuming that the negative linear correlation between F v/F m and the maximum quantum yield for photosynthesis (Φ) is proportional to that between F v/F m and αnet, it was possible to include the daily variation of αnet due to photoinhibition. To compensate for the variation of F v/F m, a representative value for each day was obtained by weighting all values of F v/F m over the diurnal period in relation to total PI. For all algal species there was a fairly good agreement between this representative value and the F v/F m value measured around noon. As the daily representative F v/F m value showed a negative linear correlation with the daily mean PI, it was possible to correct αnet for differences of daily mean PI.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002270050239
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