, Volume 69, Issue 2, pp 288–295

The analysis of photosynthesis in air and water of Ascophyllum nodosum (L.) Le Jol.

  • Andrew M. Johnston
  • John A. Raven
Original Papers

DOI: 10.1007/BF00377636

Cite this article as:
Johnston, A.M. & Raven, J.A. Oecologia (1986) 69: 288. doi:10.1007/BF00377636


The photosynthetic characteristics for the intertidal macroalga Ascophyllum nodosum were examined in air and water. Under ambient conditions of temperature (10° C) inorganic carbon concentrations (15.63 mmol CO2 m-3 or 2.0 mol TIC m-3) and light (500 μmol photons m-2 s-1) photosynthesis was slightly greater by the exposed alga than by the submerged alga. In both environments photosynthesis was light saturated at 200 μmol photons m-2 s-1. The relationship between CO2 concentration and photosynthesis in air could be accurately analysed using Michaelis-Menten kinetics, although the range of concentrations used were not saturating. In contrast the application of the Lineweaver-Burk and Woolf plots to aquatic photosynthesis was not suitable as the experimental data was similar to the Blackman type curves and not rectangular hyperbolae. This was reflected by the applicability of the Hill-Whittingham equation to describe the photosynthesis curves. The effect of unstirred layers and other limiting factors is discussed in relation to the kinetic parameters, Vmax and Km.

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Andrew M. Johnston
    • 1
  • John A. Raven
    • 1
  1. 1.Department of Biological SciencesDundee UniversityDundeeUK