term measurements (Fig. 3.6 a & c). Or the activity of the dark-reaction system may
be increased at high light intensities (driven by increased availability of light-
energized reactants – ATP, NADPH), causing the Pmax value to rise in short-term
comparisons for Cyclotella (Fig. 3.6b).
Fig. 3.6 Three types of acclimation to different light intensities, all in terms of
photosynthesis per cell, not per unit chlorophyll. Changing chlorophyll per cell is part
of the acclimation process. (a) Chlamydomonas moevuss. (b) Cyclotella
meneghiniana. (c) Phaeodactylum tricornutum. Light intensities were 12 (dots), 5
(circles) and 0.7 (triangles) klux.
(^) (a after Jørgensen 1969, b after Jørgensen 1964, c after Beardall & Morris 1976.)