Summary
Competition for light among species in a mixed canopy can be assessed quantitatively by a simulation model which evaluates the importance of different morphological and photosynthetic characteristics of each species. A model was developed that simulates how the foliage of all species attenuate radiation in the canopy and how much radiation is received by foliage of each species. The model can account for different kinds of foliage (leaf blades, stems, etc.) for each species. The photosynthesis and transpiration for sunlit and shaded foliage of each species is also computed for different layers in the canopy. The model is an extension of previously described single-species canopy photosynthesis simulation models. Model predictions of the fraction of foliage sunlit and interception of light by sunlit and shaded foliage for monoculture and mixed canopies of wheat (Triticum aestivum) and wild oat (Avena fatua) in the field compared very well with measured values. The model was used to calculate light interception and canopy photosynthesis for both species of wheat/wild oat mixtures grown under normal solar and enhanced ultraviolet-B (290–320 nm) radiation (UV-B) in a glasshouse experiment with no root competition. In these experiments, measurements showed that the mixtures receiving enhanced UV-B radiation had a greater proportion of the total foliage area composed of wheat compared to mixtures in the control treatments. The difference in species foliage area and its position in the canopy resulted in a calculated increase in the portion of total canopy radiation interception and photosynthesis by wheat. This, in turn, is consistent with greater canopy biomass of wheat reported in canopies irradiated with supplemental UV-B.
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References
Allen LH (1974) A model of light penetration in a wide row crop. Agron J 66:41–47
Barnes PW, Jordan PW, Gold WG, Flint SD, Caldwell MM (1988) Competition, morphology and canopy structure in wheat (Triticum aestivum L.) and wild oat (Avena fatua L.) exposed to enhanced ultraviolet-B radiation. Funct Ecol 2:319–330
Barnes PW, Beyschlag W, Ryel RJ, Flint SD, Caldwell MM (1990) Plant competition for light analyzed with a multispecies canopy model. III. Influence of canopy structure in mixtures and monocultures of wheat and wild oat. Oecologia in press
Beyschlag W, Barnes PW, Flint SD, Caldwell MM (1988) Enhanced UV-B irradiation has no effect on photosynthetic characteristics of wheat (Triticum aestivum L.) and wild oat (Avena fatua L.) under greenhouse and field conditions. Photosynthetica 22:516–525
Beyschlag W, Barnes PW, Ryel RJ, Caldwell MM, Flint SD (1990) Plant competition for light analyzed with a multispecies canopy model. II. Influence of photosynthetic characteristics on mixtures of wheat and wild oat. Oecologia in press
Boller BC, Nösberger J (1985) Photosynthesis of white clover leaves as influenced by canopy position, leaf age, and temperature. Ann Bot (London) 56:19–27
Burt JE, Luther FM (1979) Effect of receiver orientation on erythema dose. Photochem Photobiol 29:85–91
Caldwell MM (1977) The effects of solar UV-B radiation (280–315 nm) on higher plants: implications of stratospheric ozone reduction. In: Castellani A (ed) Research in Photobiology. Plenum Publishing Corporation, New York, pp 597–607
Caldwell MM (1987) Plant architecture and resource competition. In: Schulze E-D, Zwölfer H (eds) Ecological studies, vol 61. Springer, Berlin Heidelberg New York, pp 164–179
Caldwell MM, Meister HP, Tenhunen JD, Lange OL (1986) Canopy structure, light microclimate and leaf gas exchange of Quercus coccifera L. in a Portuguese macchia: measurements in different canopy layers and simulations with a canopy model. Trees 1:25–41
Charles-Edwards DA, Thorpe MR (1976) Interception of diffuse and direct beam radiation by a hedgerow apple orchard. Ann Bot (London) 40:603–613
Chazdon RL, Fetcher N (1984) Photosynthetic light environments in a lowland tropical rain forest in Costa Rica. J Ecol 72:553–564
Dahlman RC (1985) Modeling needs for predicting responses to CO2 enrichment: Plants, communities, and ecosystems. Ecol Modelling 29:77–106
Duncan WG, Loomis RS, Williams WA, Hanau R (1967) A model for simulating photosynthesis in plant communities. Hilgardia 38:181–205
Farquhar GD, von Caemmerer S, Berry JA (1980) A biochemical model of photosynthetic CO2 assimilation in leaves of C3 species. Planta 149:78–90
Farquhar GD, von Caemmerer S (1982) Modelling of photosynthetic response to environmental conditions. In: Lange OL, Nobel PS, Osmond CB, Zeigler H (eds) Physiological Plant Ecology II, Encyclopedia Plant Physiol vol 12B. Springer, Berlin Heidelberg New York, pp 549–587
Farquhar GD, Wong SC (1984) An empirical model of stomatal conductance. Aust J Plant Physiol 11:191–210
Field C, Mooney HA (1983) Leaf age and seasonal effects of light, water, and nitrogen use efficiency in a California shrub. Oecologia 56:348–355
Ford ED, Diggle PJ (1981) Competition for light in a plant monoculture modelled as a spatial stochastic process. Ann Bot (London) 48:481–500
Gold WG, Caldwell MM (1983) The effects of ultraviolet-B radiation on plant competition in terrestrial ecosystems. Physiol Plant 58:435–444
Gutschick VP, Wiegel FW (1988) Optimizing the canopy photosynthetic rate by patterns of investment in specific leaf mass. Am Nat 132:67–86
Harper JL, Clatworthy JN (1963) The competitive biology of closely related species IV Analysis of the growth of Trifolium repens and T. fragiferum in pure and mixed populations. J Exp Bot 14:172–190
Idso SB, deWit CT (1970) Light relations in plant canopies. Appl Optics 9(1):177–184
Joggi D, Hofer U, Nösberger J (1983) Leaf area index, canopy structure and photosynthesis of red clover (Trifolium pratense L.). Plant Cell Environ 6:611–616
Juhani H, Kellomaki S (1984) Comparison of growth strategies of two competing plant species in forest ground cover. Ecol Modelling 23:135–150
Keener ME, McCree KJ (1975) A test of the Duncan model of photosynthesis in plant communities. Crop Sci 15:214–216
Lee TD, Bazzaz FA (1980) Effects of defoliation and competition on growth of Pinaceae species. Can J For Res 11:243–248
Lemeur R (1973) A method for simulating the direct solar radiation regime of sunflower, Jerusalem artichoke, corn and soybeans using actual stand structure data. Agric Meteorl 12:229–247
Mann JE, Curry GL, Sharp PJH (1979) Light interception by isolated plants. Agric Meteorl 20:205–214
Mann JE, Curry GL, De Michele DW, Baker DN (1980) Light penetration in a row crop of random plant spacing. Agron J 72:131–142
McMurtrie R, Wolf L (1983) A model of competition between trees and grass for radiation, water and nutrients. Ann Bot (London) 52:449–458
Monsi M, Saeki T (1953) Über den Lichtfaktor in den Pflanzengesellschaften und seine Bedeutung für die Stoffproduktion. Jpn J Bot 14:22–52
Mueggler WF (1972) Influence of competition on the response of bluebunch wheatgrass to clipping. J Range Manag 25:88–92
Norman JM (1978) Modeling the complete crop canopy. In: Barfield BJ, Gerber JF (eds) Modification of the aerial environment of crops. Am Soc Agric Eng, St Joseph, pp 249–277
Norman JM (1980) Interfacing leaf and canopy light interception models. In: Hesketh JD, Jones JW (eds) Predicting Photosynthesis for Ecosystem Models, vol II. CRC Press Inc, Boca Raton, FL, pp 49–67
Norman JM, Tanner CB (1969) Transient light measurements in plant canopies. Agron J 61:847–849
Norman JM, Welles JM (1983) Radiative transfer in an array of canopies. Agron J 75:481–488
Norman JM, Miller EE, Tanner CB (1971) Light intensity and sunfleck size distribution in plant communities. Agron J 63:743–748
Reynolds JF, Acock B (1985) Predicting the resonnse of plants to increasing carbon dioxide: A critique of plant growth models. Ecol Modelling 29:107–129
Reynolds JF, Dougherty RL, Tenhunen JD, Harley PC (1988) PRECO: A model for the simulation of plant response to elevated CO2. Report # 42, Response of vegetation to carbon dioxide series, Carbon Dioxide Research Division, U.S. Department of Energy, Washington, D.C.
Rimmington GM (1984) A model of the effect of interspecies competition for light on dry-matter production. Aust J Plant Physiol 11:277–286
Ross PJ, Henzell EF, Ross DR (1972) Effects of nitrogen and light in grass-legume pastures, a systems analysis approach. J Appl Ecol 9:535–556
Tenhunen JD, Yocum CS, Gates DM (1976) Development of a photosynthesis model with an emphasis on ecological applications. I. Theory. Oecologia 26:89–100
Tenhunen JD, Meyer A, Lange OL, Gates DM (1980) Development of a photosynthesis model with an emphasis on ecological applications. V. Test of the applicability of a steady-state model to description of net photosynthesis of Prunus armeniaca under field conditions. Oecologia 45:147–155
Wierman CA, Oliver CD (1979) Crown stratification by species in even-aged mixed stands of Douglas-fir-western hemlock. Can J For Res 9:1–9
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Ryel, R.J., Barnes, P.W., Beyschlag, W. et al. Plant competition for light analyzed with a multispecies canopy model. Oecologia 82, 304–310 (1990). https://doi.org/10.1007/BF00317475
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DOI: https://doi.org/10.1007/BF00317475