M.J. Perry K.E. Bencala M.C. Talbot D. H. Peterson 1987 <p><span>A simple exponential equation is used to describe photosynthetic rate as a function of light intensity for a variety of unicellular algae and higher plants where photosynthesis is proportional to (1-e</span>^−β1<span>). The parameter β (</span><span class="math"><span id="MathJax-Element-1-Frame" class="MathJax_SVG" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot;><mtext>=I</mtext><msub><mi></mi><mn><mtext>k</mtext></mn></msub><msup><mi></mi><mn>&amp;#x2212;1</mn></msup></math>"><span class="MJX_Assistive_MathML">=I_k⁻¹</span></span></span><span>) is derived by a simultaneous curve-fitting method, where&nbsp;</span><i>I</i><span>&nbsp;is incident quantum-flux density. The exponential equation is tested against a wide range of data and is found to adequately describe&nbsp;</span><i>P vs. I</i><span>&nbsp;curves. The errors associated with photosynthetic parameters are calculated. A simplified statistical model (Poisson) of photon capture provides a biophysical basis for the equation and for its ability to fit a range of light intensities. The exponential equation provides a non-subjective simultaneous curve fitting estimate for photosynthetic efficiency (</span><i>a</i><span>) which is less ambiguous than subjective methods: subjective methods assume that a linear region of the&nbsp;</span><i>P vs. I</i><span>&nbsp;curve is readily identifiable. Photosynthetic parameters β and&nbsp;</span><i>a</i><span>&nbsp;are used widely in aquatic studies to define photosynthesis at low quantum flux. These parameters are particularly important in estuarine environments where high suspended-material concentrations and high diffuse-light extinction coefficients are commonly encountered.</span></p> application/pdf 10.1016/0272-7714(87)90154-5 en Elsevier Phytoplankton productivity in relation to light intensity: A simple equation article