University of California

A model for simulating photosynthesis in plant communities


W. G. Duncan
R. S. Loomis
W. A. Williams
R. Hanau

Authors Affiliations

W. G. Duncan was Associate Professor of Agronomy, University of Kentucky; R. S. Loomis was Associate Professor of Agronomy, Davis; W. A. Williams was Professor of Agronomy, Davis; R. Hanau was Professor of Physics, University of Kentucky.

Publication Information

Hilgardia 38(4):181-205. DOI:10.3733/hilg.v38n04p181. March 1967.

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In this paper, the amount of photosynthesis accomplished by a canopy of leaves is predicted from the properties of individual leaves. Theories are developed for the penetration of direct and diffuse sunlight through a foliage composed of many layers of leaves, each having known orientation, area, reflection and transmission characteristics. From this, the illumination of each leaf at a particular time of day (sun elevation) and thus its photosynthesis, is determined. Hourly observations are summed for estimates of daily photosynthesis by plant communities.

An immense number of calculations are required in such a model, but an IBM 7044-type computer can complete them in about six seconds. Solutions to a number of real and hypothetical problems are presented. These provide new insights into the photosynthetic behavior of plant communities.

Literature Cited

Alberda T., Sibma L. Dry matter production and light interception of crop surfaces. II. Relation between growth and length of grass. Jaarb. Inst. biol. scheik. Onderz. LandbGewass. 1962. pp.47-58.

Black J. N. The interrelationship of solar radiation and leaf area index in determining the rate of dry matter production of swards of subterranean clover (Trifolium subterraneum L.). Aust. Jour. Agr. Res. 1963. 14:20-38.

Brougham R. W. Effect of intensity of defoliation on regrowth of pasture. Aust. Jour. Agr. Res. 1956. 7:377-87. DOI: 10.1071/AR9560377 [CrossRef]

Davidson J. L., Donald C. M. The growth of swards of subterranean clover with particular reference to leaf area. Aust. Jour. Agr. Res. 1958. 9:53-72. DOI: 10.1071/AR9580053 [CrossRef]

Davidson J. L., Philip J. R. Light and pasture growth. Climatology and microclimatology. 1958. Paris: UNESCO. Proc. Canberra Sym. (1956). Arid Zone Research XI

Hesketh J. D. Limitations to photosynthesis responsible for differences among species. Crop. Sci. 1963. 3:493-96.

Kasanga H., Monsi M. On the light transmission of leaves and its meaning for the production of matter in plant communities. Jap. Jour. Bot. 1954. 14:304-24.

Lemon E. R. Photosynthesis under field conditions. II. An aerodynamic method for determining the turbulent carbon dioxide exchange between the atmosphere and a corn field. Agron. Jour. 1960. 52:697-703. DOI: 10.2134/agronj1960.00021962005200120009x [CrossRef]

Loomis R. S., Williams W. A. Maximum crop productivity: An estimate. Crop Sci. 1963. 3:67-72.

Ludwig L. J., Saeki T., Evans L. T. Photosynthesis in artificial communities of cotton plants in relation to leaf area. I. Experiments with progressive defoliation of mature plants. Aust. Jour. Biol. Sci. 1965. 18:1103-118.

Monsi M. Dry-matter reproduction in plants: I. Schemata of dry-matter reproduction. Bot. Mag., Tokyo. 1960. 73:81-90.

Monsi M., Saeki T. Über den Lichtfaktor in den Pflanzengesellschaften und seine Bedeutung für die Stoffproduktion. Jap. Jour. Bot. 1953. 14:22-52.

Moss D. N., Musgrave R. B., Lemon E. R. Photosynthesis under field conditions. III. Some effects of light, carbon dioxide, temperature, and soil moisture on photosynthesis, respiration, and transpiration of corn. Crop Sci. 1961. 1:83-87.

Moss D. N. Optimum lighting of leaves. Crop. Sci. 1964. 4:131-36.

Monteith J. L. Measurement and interpretation of carbon dioxide fluxes in the field. Neth. Jour. Agr. Sci. 1962. 10:334-46.

Monteith J. L. Light distribution and photosynthesis in field crops. Ann. Bot. N.S. 1965. 29:17-37.

Nichiporovich A. A. Properties of plant crops as an optical system. Soviet Pl. Physiol. 1961. 8:428-35.

Rabinowitch E. I. Photosynthesis. Vol. I. 1945. New York: Interscience Publishers, Inc. 599p.

Rabinowitch E. I. Photosynthesis. 1951. II: New York: Interscience Publishers, Inc. 1208p. Part 1. DOI: 10.1146/annurev.pp.03.060152.001305 [CrossRef]

Reeve J. E. Appendix on derivation of formulae (in “Inclined Point Quadrats,” by J. Warren Wilson). New Phytol. 1960. 59:1-8.

Stanhill G. The effect of environmental factors on the growth of alfalfa. Neth. Jour. Agr. Sci. 1962. 10:247-53.

Takeda T. Studies on the photosynthesis and production of dry matter in the community of rice plants. Jap. Jour. Bot. 1961. 17:403-37.

Thomas M. D., Hill G. R., Franck J., Loomis W. E. Photosynthesis under field conditions. Photosynthesis in plants. 1949. Ames: Iowa State University Press. DOI: 10.1104/pp.12.2.285 [CrossRef]

Verhagen A. M. W., Wilson J. H., Britten E. J. Plant production in relation to foliage illumination. Ann. Bot. N. S. 1963. 27:627-40.

Watson D. J. Comparative physiological studies on the growth of field crops. I. Variation in net assimilation rate and leaf area between species and varieties, and within and between years. Ann. Bot. N. S. 1947. 11:47-76.

Watson D. J. The dependence of net assimilation rate on leaf area index. Ann. Bot. N. S. 1958. 22:37-55.

Watson D. J., Witts K. J. The net assimilation rates of wild and cultivated beets. Ann. Bot. N. S. 1959. 23:431-39.

Williams W. A., Loomis R. S., Lepley C. R. Vegetative growth of corn as affected by population density. I. Productivity in relation to interception of solar radiation. Crop. Sci. 1965a. 5:211-15.

Williams W. A., Loomis R. S., Lepley C. R. Vegetative growth of corn as affected by population density. II. Components of growth, net assimilation rate and leaf area index. Crop Sci. 1965b. 5:215-19.

Wilson J. Warren. Inclined point quadrats. New Phytol. 1960. 59:1-8. DOI: 10.1111/j.1469-8137.1960.tb06195.x [CrossRef]

Wit C. T. de. Potential photosynthesis of crop surfaces. Neth. Jour. Agr. Sci. 1959. 7:141-49.

Wit C. T. de. Photosynthesis of leaf canopies. Versl. landbouwk. Onderz. Ned. 1965. 663:57 DOI: 10.1111/j.1469-8137.2009.03061.x [CrossRef]

Duncan W, Loomis R, Williams W, Hanau R. 1967. A model for simulating photosynthesis in plant communities. Hilgardia 38(4):181-205. DOI:10.3733/hilg.v38n04p181
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