Anten, N P R (1997) Modelling canopy photosynthesis using parameters determined from simple non-destructive measurements. Ecological Research, 12 (1). pp. 77-88.
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Abstract
Most models for canopy photosynthesis require a large number of parameters as input which have to be determined by means of direct measurements. Such measurements are usually expensive, time consuming and destructive. The objective of the present study was, therefore, to develop a simple but accurate canopy photosynthesis model based on a minimum number of parameters that can be determined nondestructively. The results from previous studies were used to derive an empirical expression which describes the variation in leaf photosynthetic capacity (Pro) as a function of the light distribution in the canopy. The light distribution itself was calculated with a simple model which assumes only three leaf angle classes (0-30 ~ 30-60 ~ and 60-90 ~ The leaf area index was determined indirectly from measurements of direct radiation below the canopy. The result was a model for canopy photosynthesis that requires only a few parameters. These parameters are the leaf photosynthetic capacity at the top of the canopy, the relative frequency of leaves in each of the three leaf angle classes, and the fraction of direct radiation below the canopy. Each of these parameters can be determined by means of simple non-destructive measurements. The model was applied to dense stands of two monocotyledonous species: rice (Oryza sativa L.) and pearl millet (Pennisetum americanum (L) K. Schum.). The rates of canopy photosynthesis thus calculated were compared to those obtained with a more elaborate reference model. The differences between the values obtained with the two models were small. The present photosynthesis model can, therefore, be considered to be a suitable alternative for the more elaborate model. It was further discussed that, since the model is based on purely non-destructive measurements, it will be particularly useful in cases where it is required to estimate canopy photosynthesis at regular intervals over a length of time or in stands of vegetation that cover large areas of land.
| Item Type: | Article |
|---|---|
| Additional Information: | I thank Marinus Werger, Heinjo During, Feike Schieving and Jan Goudriaan for their constructive comments. I am also grateful to Ernesto Medina of the Instituto Venezolano de Investigaciones Cientificas (IVIC) and Orlando Guenni of the Fondo Nacional de Investigaciones Agropecuarias (FONAIAP) for advice and kindly supplying research facilities. Peter Schuffelen provided technical assistance. This work was supported by grant W86-104 of the Netherlands Foundation for the Advancement of Tropical Research (WOTRO). Part of the work was completed at: Centro de Ecologia y Ciencias Ambientales, Instituto Venezolano de Investigaciones Cientificas, Aptdo. 21827 Caracas 1020 A, Venezuela. |
| Uncontrolled Keywords: | canopy, model, photosynthesis, Oryza sativa, Pennisetum americanum |
| Author Affiliation: | Utrecht University Department of Plant Ecology and Evolutionary Biology PO Box 800. 84 NL-3508 TB Utrecht The Netherlands |
| Subjects: | Agricultural Engineering |
| Divisions: | General |
| Depositing User: | Mr Siva Shankar |
| Date Deposited: | 28 Mar 2012 10:13 |
| Last Modified: | 28 Mar 2012 10:13 |
| Official URL: | http://dx.doi.org/10.1007/BF02523613 |
| URI: | http://eprints.icrisat.ac.in/id/eprint/4316 |
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