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Photosynthesis response by phytoplankton to sunlight variability 1
Author(s) -
Marra John,
Heinemann Kristina
Publication year - 1982
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1982.27.6.1141
Subject(s) - photosynthesis , irradiance , phytoplankton , sunrise , sunlight , environmental science , atmospheric sciences , solar irradiance , botany , biology , physics , ecology , optics , nutrient
Photosynthetic oxygen evolution and solar irradiance have been measured for phytoplankton cultures kept in a south‐facing window greenhouse. Sunrise‐sunset periods are considered; measurement and analytical techniques allow examination of a frequency range of ≈w0.2–3 cy · h −1 , and, in one instance, up to 10 cy · h −1 . On sunny days there are morning maxima and afternoon depressions in photosynthesis. Photosynthesis closely tracks irradiance on cloudy and variable days. Cross‐spectral analysis of data from variable days shows that photosynthesis responds to changes in irradiance (at 1–10 cy · h −1 ) rather than integrating past irradiance values. A physiological explanation suggested for this behavior concerns the redox characteristics of electron carriers involved in noncyclic photosynthetic electron transport. The ecological significance of the time‐dependent behavior of photosynthesis is that it compensates for the heterogeneous and uncertain light environment experienced by phytoplankton.