
%0 Journal Article
%A Johnson, IR 
%A Parsons, AJ 
%A Ludlow, MM 
%T Modelling Photosynthesis in Monocultures and Mixtures
%J Functional Plant Biology
%D 1989/12/01
%V 16
%N 6
%P 501-516
%K 
%R https://doi.org/10.1071/PP9890501
%U https://www.publish.csiro.au/paper/PP9890501 
%X A comparison is made between two models of canopy photosynthesis for monocultures that differ in their treatment of the variation of the rate of single-leaf photosynthesis in response to the irradiance in which the leaves have grown. Both are shown to be deficient, and a simple modification to one that results in a much improved performance is presented. The theory uses the non-rectangular hyperbola for the rate of single-leaf photosynthesis and incorporates the Monsi-Saeki approach for the light-intercepting characteristics of the canopy. The model is then extended to describe the photosynthesis of mixed canopies, which requires knowledge of the relative position of each leaf-area component within the sward. Analytical expressions can be derived for the case where the leaf-area components are homogeneously distributed relative to each other through the depth of the canopy. This is shown to be a good representation of leaf-area distributions in continuously grazed temperate grass-clover swards as well as frequently cut tropical grass-legume swards, and so is an important special case. 
