Aase, J. K. and F. H. Siddoway. 1980. Determining winter wheat stand densities using spectral reflectance measurements. Agronomy Journal 72:149-152.

Abrams, M. D. and M. E. Kubiske. 1990. Leaf structural characteristics of 31 hardwood and conifer tree species in central Wisconsin: influence of light regime and shade-tolerance rank. Forest Ecology and Management 31:245-253.

Acock, B., D. A. Charles-Edwards, and S. Sawyer. 1979. Growth response of a Chrysanthemum crop to the environment. III. Effects of radiation and temperature on dry matter partitioning and photosynthesis. Annals of Botany 44:289-300.

Allen, L. H. Jr, H. W. Gausman, and W. A. Allen. 1975. Solar ultraviolet radiation in terrestrial plant communities. Journal of Environmental Quality 4:285-294.

Anderson, M. C. 1964. Light relations of terrestrial plant communities and their measurement. Biological Review 39:425-486.

Anderson, W. K., R. C. G. Smith, and J. R. McWilliam. 1978. A systems approach to the adaptation of sunflower to new environments. II. Effects of temperature and radiation on growth and yield. Field Crops Research 1:153-163.

Andrews, M., R. Box, S. McInroy, and J. A. Raven. 1984. Growth of Chara hispida. II. Shade adaptation. Journal of Ecology 72:885-895.

Arnott, J. T. 1979. Effect of light intensity during extended photoperiod on growth of amabilis fir, mountain hemlock, and white and Engelmann spruce seedlings. Canadian Journal of Forest Research 9:82-89.

Assmann, S. M. and D. A. Grantz. 1990. Stomatal response to humidity in sugarcane and soybean: effect of vapour pressure difference on the kinetics of the blue light response. Plant, Cell and Environment 13:163-169.

Augspurger, C. K. 1984. Light requirements of neotropical tree seedlings: a comparative study of growth and survival. Journal of Ecology 72:777-795.

Baldocchi, D. D., B. A. Hutchison, D. R. Matt, and R. T. McMillen. 1985. Canopy radiative transfer models for spherical and known leaf inclination angle distributions: A test in an oak-hickory forest. Journal of Applied Ecology 22:539-555.

Becker, P. and A. P. Smith. 1990. Spatial autocorrelation of solar radiation in a tropical moist forest understory. Agricultural and Forest Meteorology 52:373-.

Becker, P., D. W. Erhart, and A. P. Smith. 1989. Analysis of forest light environments. Part I. Computerized estimation of solar radiation from hemispherical canopy photographs. Agricultural and Forest Meteorology 44:217-.

Berg, V. S. and S. Heuchelin. 1990. Leaf orientation of soybean seedlings. I. Effect of water potential and photosynthetic photon flux density on paraheliotropism. Crop Science 30:631-638.

Besford, R. T. 1986. Changes in some Calvin cycle enzymes of the tomato during acclimation to irradiance. Journal of Experimental Botany 37:200-210.

Beyschlag, W., P. W. Barnes, R. Ryel, M. M. Caldwell, and S. D. Flint. 1990. Plant competition for light analyzed with a multispecies canopy model. II. Influence of photosynthetic characteristics on mixtures of wheat and wild oat. Oecologia 82:374-380.

Billings, W. D. and R. J. Morris. 1951. Reflection of visible and infrared radiation from leaves of different ecological groups. American Journal of Botany 38:327-331.

Birkebak, R. and R. Birkebak. 1964. Solar radiation characteristics of tree leaves. Ecology 45:646-649.

Blumthaler, M. and W. Ambach. 1990. Indication of increasing solar ultraviolet-B radiation flux in alpine regions. Science 248:206-208.

Boisvert, J. B., H. N. Hayhoe, and P. A. Dube. 1990. Improving the estimation of global solar radiation across Canada. Agricultural and Forest Meteorology 52:275-286.

Bonan, G. B. 1989. A computer model of the solar radiation, soil moisture, and soil thermal regimes in boreal forests. Ecological Modelling 45:275-.

Borghetti, M., G. G. Vendramin, R. Giannini, and A. Schettino. 1989. Effects of stratification, temperature and light on germination of Pinus leucodermis. Oecologia Plantarum 10:45-56.

Brach, E. J., A. R. Mack, and V. R. Rao. 1979. Normalization of radiance data for studying crop spectra over time with a mobile field spectro-radiometer. Canadian Journal of Remote Sensing 5:33-42.

Brown, J. C., H. M. Cathey, J. H. Bennett, and R. W. Thimijan. 1979. Effect of light quality and temperature on Fe3+ reduction. Agronomy Journal 71:1015-1021.

Brunner, U. and B. M. Eller. 1977. Spectral properties of juvenile and adult leaves of Piper betle and their ecological significance. Physiological Plantarum 41:22-24.

Burnside, C. A. and R. H. Böhning. 1957. The effect of prolonged shading on the light saturation curves of apparent photosynthesis in sun plants. Plant Physiology 32:61-63.

Byrne, G. F., J. J. Landsberg, and M. L. Benson. 1986. The relationship of above-ground dry matter accumulation by Pinus radiata to intercepted solar radiation and soil water status. Agricultural and Forest Meteorology 37:63-73.

Caldwell, M. M., T. J. Dean, R. S. Nowak, R. S. Dzurec, and J. H. Richards. 1983. Bunchgrass architecture, light interception, and water-use efficiency: Assessment by fiber optic point quadrat and gas exchange. Oecologia 59:178-184.

Caldwell, M. M., D. A. Johnson, and M. Fareed. 1978. Constraints of tundra productivity: photosynthetic capacity in relation to solar radiation utilization and water stress in arctic and alpine tundras. Pages 323-342 in L.L. Tieszen, editor. Vegetation and production ecology of an Alaskan arctic tundra, ecological studies 29. Springer-Verlag, New York, New York, USA.

Caldwell, M. M., R. Robberecht, and W. D. Billings. 1980. A steep latitudinal gradient of solar ultraviolet-B radiation in the arctic-alpine life zone. Ecology 61:600-611.

Campbell, W. J., L. H. Jr Allen, and B. Bowes. 1990. Response of soybean canopy photosynthesis to CO2 concentration, light, and temperature. Journal of Experimental Botany 41:427-433.

Cannell, M. G. R., R. Milne, L. J. Sheppard, and M. H. Unsworth. 1987. Radiation interception and productivity of willow. Journal of Applied Ecology 24:261-278.

Cen, J. -P. and J. F. Bornman. 1990. The response of bean plants to UV-B radiation under different irradiances of background visible light. Journal of Experimental Botany 41:1489-1495.

Chazdon, R. L. and C. B. Field. 1987. Photographic estimation of photosynthetically active radiation: evaluation of a computerized technique. Oecologia 73:525-532.

Christ, R. A. 1978. The elongation of wheat leaves. II. Effect of sudden light change on the elongation rate. Journal of Experimental Botany 29:611-618.

Clark, J. B. and G. R. Lister. 1975. Photosynthetic action spectra of trees. II. The relationship of cuticle structure to the visible and ultraviolet spectral properties of needles from four coniferous species. Plant Physiology 55:407-412.

Dahlem, T. S. and R. E. J. Boerner. 1987. Effects of canopy light gap and early emergence on the growth and reproduction of Geranium maculatum. Canadian Journal of Botany 65:242-245.

Daughtry, C. S. T., V. C. Vanderbilt, and V. J. Pollara. 1982. Variability of reflectance measurements with sensor altitude and canopy type. Agronomy Journal 74:744-751.

Dave, J. V. 1980. Simulation colorimetry of the earth-atmosphere system. Remote Sensing of Environment 9:301-324.

Derr, V. E. 1980. Attenuation of solar energy by high, thin clouds. Atmospheric Environment 14:719-729.

Drew, A. P. and W. K. Ferrell. 1977. Morphological acclimation to light intensity in Douglas-fir seedlings. Journal of Canadian Botany 55:2033-2042.

Donahue, R. and V. S. Berg. 1990. Leaf orientation of soybean seedlings: II. Receptor sites and light stimuli. Crop Science 30:638-643.

Duke, S. O. and S. H. Duke. 1979. Photosynthetic independence of initial light-caused increase in extractable nitrate reductase activity from maize seedlings. Plant, Cell and Environment 20:1371-1380.

Durrenberger, R. W. and A. J. Brazel. 1976. Need for better solar radiation data base. Science 193:1154-1155.

Ehleringer, J. R., C. B. Field, Z.-F. Lin, and C.-Y. Kou. 1986. Leaf carbon isotope and mineral composition in subtropical plants along an irradiance cline. Oecologia 70:520-526.

Ekelund, N. G. A. 1990. Effects of UV-B radiation on growth and motility of four phytoplankton species. Physiologia Plantarum 78:590-594.

Eller, B. M. 1982. Solar radiation absorbed by Argyroderma pearsonii (N.E. Brown) Schw. during growing and rest period. Berichte der Deutschen Botanischen Gesellschaft 95:333-340.

Eller, B. M. and W. Koch. 1977. Global radiation in gas exchange chambers and outside. Photosynthetica 11:268-275.

Eller, B. M. and P. Willi. 1977. The significance of the wax bloom on leaves of Kalanchoe pumila Baker for the absorption of global radiation. Flora 166:461-474.

Enz, J. W., L. J. Brun, and J. K. Larsen. 1988. Evaporation and energy balance for bare and stubble covered soil. Agricultural and Forest Meteorology 43:59-70.

Ewel, J., F. Benedict, C. Berish, and B. Brown. 1982. Leaf area, light transmission, roots and leaf damage in nine tropical plant communities. Agro-Ecosystems 7:305-326.

Fasheun, A. 1982. Interception of radiation and growth efficiency in field beans (Vicia faba L.). Agricultural Meteorology 26:221-229.

Fenner, M. 1980. The induction of a light requirement in Bidens pilosa seeds by leaf canopy shade. New Phytologist 84:103-106.

Fenner, M. 1980. The inhibition of germination of Bidens pilosa seeds by leaf canopy shade in some natural vegetation types. New Phytologist 84:95-101.

Fitter, D. J., P. H. Knapp, and J. W. Wilson. 1980. Stand structure and light penetration. IV. A sensor for measuring photosynthetically active radiation. Journal of Applied Ecology 17:183-193.

Flint, A. L. and S. W. Childs. 1987. Calculation of solar radiation in mountainous terrain. Agricultural and Forest Meteorology 40:233-249.

Floyd, B. W., J. W. Burely, and R. D. Noble. 1978. Foliar developmental effects on forest floor light quality. Forest Science 24:445-451.

Forseth, I. N. and J. R. Ehleringer. 1982. Ecophysiology of two solar-tracking desert winter annuals. I. Photosynthetic acclimation to growth temperature. Australian Journal of Plant Physiology 9:321-332.

Frankland, B. and R. J. Letendre. 1978. Phytochrome and effects of shading on growth of woodland plants. Photochemistry and Photobiology 27:223-230.

Frederick, J. E. and H. E. Snell. 1988. Ultraviolet radiation levels during the Antarctic spring. Science 241:438-440.

Fukai, S. and J. H. Silsbury. 1977. Effects of irradiance and solar radiation on dry matter growth and net CO2 exchange at a constant temperature. Australian Journal of Plant Physiology 4:485-497.

Gallagher, J. N. and P. V. Biscoe. 1979. Field studies of cereal leaf growth. III. Barley leaf extension in relation to temperature, irradiance, and water potential. Journal of Experimental Botany 30:645-655.

Gast, P. R., A. S. Jursa, J. Castelli, S. Basu, and J. Aarons. 1965. Solar electromagnetic radiation. Pages 16-1 - 16-38 in S.L. Valley, editor. Handbook of geophysics and space environments. United States Air Force Cambridge Research Laboratories. McGraw-Hill Book Company, New York, New York, USA.

Gausman, H. W. 1985. Plant leaf optical properties in visible and near-infrared light. Texas Tech Press, Lubbock, Texas, USA.

Gausman, H. W. and R. Cardenas. 1973. Light reflectance by leaflets of pubescent, normal, and glabrous soybean lines. Agronomy Journal 65:837-838.

Geller, G. N. and P. S. Nobel. 1987. Comparative cactus architecture and PAR interception. American Journal of Botany 74:998-1005.

Granger, J. E. and R. E. Schulze. 1977. Incoming solar radiation patterns and vegetation response: examples from the Natal Drakensberg. Vegetatio 35:47-54.

Green, C. F. 1984. A description of seasonal interception of radiation by crops while the canopy is expanding. Photosynthetica 18:418-420.

Green, C. F. and C. N. Deuchar. 1985. On improved tube solarimeter construction. Journal of Experimental Botany 36:690-693.

Green, C. F., P. D. Hebblethwaite, and D. A. Ison. 1985. A quantitative analysis of varietal and moisture status effects on the growth of Vicia faba in relation to radiation absorption. Annals of Applied Biology 106:143-155.

Gross, K. L. 1985. Effects of irradiance and spectral quality on the germination of Verbascum thapsus L. and Oenothera bienis L. seeds. New Phytologist 101:531-541.

Gross, L. J. and B. F. Chabot. 1979. Time course of photosynthetic response to changes in incident light energy. Plant Physiology 63:1033-1038.

Gueymard, C. 1989. An atmospheric transmittance model for the calculation of the clear sky beam, diffuse and global photosynthetically active radiation. Agricultural and Forest Meteorology 45:215-229.

Gueymard, C. 1986. Monthly averages of the daily effective optical air mass and solar related angles for horizontal or inclined surfaces. Journal of Solar Energy Engineering 108:320-324.

Hader, D. P. and M. Hader. 1991. Effects of solar and artificial UV radiation on motility and pigmentation in the marine Cryptomonas maculata. Environmental and Experimental Botany 31:33-.

Hariri, M. and J. Brangeon. 1977. Light-induced adaptive responses under greenhouse conditions in the fern Pteris cretica var. ouvrardii. I. Structural and infrastructural features. Physiologia Plantarum 41:280-288.

Hasler, R. 1982. Net photosynthesis and transpiration of Pinus montana on east and north facing slopes at alpine timberline. Oecologia 54:14-22.

Hatfield, J. L. and R. E. Carlson. 1979. Light quality distributions and spectral albedo of three maize canopies. Agricultural Meteorology 20:215-226.

Heathcote, L., K. R. Bambridge, and J. S. McLaren. 1979. Specially constructed growth cabinets for simulation of the spectral photon distributions found under natural vegetation canopies. Journal of Experimental Botany 30:347-353.

Heilman, J. L. and M. R. Kress. 1987. Effects of vegetation on spectral irradiance at the soil surface. Agronomy Journal 79:765-768.

Heitor, A. and A. J. Rosa R. Biga. 1991. Thermal radiation components of the energy balance at the ground. Agricultural and Forest Meteorology 54:29-.

Hicklenton, P. R. and W. C. Oechel. 1977. The influence of light intensity and temperature on the field carbon dioxide exchange of Dicranum fuscescens in the subarctic. Arctic and Alpine Research 9:407-419.

Hirota, O. and T. Takeda. 1978. Studies on utilization of solar radiation by crop stands. III. Relationships between conversion efficiency of solar radiation energy and respiration of construction and maintenance in rice and soybean plant populations. Japanese Journal of Crop Science 47:336-343.

Holbo, H. R., S. W. Childs, and D. H. McNabb. 1985. Solar radiation at seedling sites below partial canopies. Forest Ecology and Management 10:115-124.

Hole, C. C. and R. A. Sutherland. 1990. The effect of photon flux density and duration of the photosynthetic period on growth and dry matter distribution in carrot. Annals of Botany 65:63-69.

Hutchings, M. J. 1976. Spectral transmission and the aerial profile in mature stands of Mercurialis perennis L. Annals of Botany 40:1207-1216.

Hutchison, B. A., D. R. Matt, and R. T. McMillen. 1980. Effects of sky brightness distribution upon penetration of diffuse radiation through canopy gaps in a deciduous forest. Agricultural Meteorology 22:137-147.

Iqbal, M. 1983. An introduction to solar radiation. Academic Press, Don Mills, Ontario, Canada.

Jackson, J. E. and J. W. Palmer. 1979. A simple model of light transmission and interception by discontinuous canopies. Annals of Botany 44:381-383.

Jamieson, P. D. 1979. Relationship between net and solar radiation received by pastures at Lincoln, New Zealand. New Zealand Journal of Science 22:245-247.

Jensen, J. M. 1975. Effects of corolla color change on the behavior of pollinating insects. Thesis, University of Idaho, Moscow, Idaho, USA.

Jurik, T. W. and J. M. Pleasants. 1990. The effects of light and plant size on fate of seedlings of the prairie compass plant (Silphium laciniatum L.). Functional Ecology 4:661-665.

Jurik, T. W., J. F. Chabot, and B. F. Chabot. 1979. Ontogeny of photosynthetic performance in Fragaria virginiana under changing light regimes. Plant Physiology 63:542-547.

Kartusch, R. and B. Mittendorfer. 1990. Ultraviolet radiation increases nicotine production in Nicotiana callus cultures. Journal of Plant Physiology 136:110-114.

Kendrick, R. E. and G. H. M. Kronenberg. 1986. Photomorphogenesis in plants. Martinus Nijhoff, Dordretch, The Netherlands.

Kirkpatrick, J. B., R. J. Fensham, M. Nunez, and D. M. J. S. Bowman. 1988. Vegetation-radiation relationships in the wet-dry tropics: granite hills in northern Australia. Vegetatio 76:103-112.

Klein, R. M. 1979. Reversible effects of green and orange-red radiation on plant cell elongation. Plant Physiology 63:114-116.

Kolb, T. E., T. W. Bowersox, and L. H. McCormick. 1990. Influences of light intensity on weed-induced stresses of tree seedlings. Canadian Journal of Forest Research 20:503-507.

Kollenkark, J. C., V. C. Vanderbilt, C. S. T. Daughtry, and M. E. Bauer. 1982. Influence of solar illumination angle on soybean canopy reflectance. Applied Optics 21:1179-1184.

Koppel, A. and T. Oja. 1984. Regime of diffuse solar radiation in an individual Norway spruce (Picea abies (L.) Karst.) crown. Photosynthetica 18:529-535.

Kozai, T. 1977. Direct solar light transmission into single-span greenhouses. Agricultural Meteorology 18:327-338.

Kozai, T. and M. Kimura. 1977. Direct solar light transmission into multi-span greenhouses. Agricultural Meteorology 18:339-349.

Kremer, D. F. and R. C. Sicher. 1986. Effects of temperature and irradiance on non-structural carbohydrate accumulation in barley primary leaves. Physiologia Plantarum 66:365-369.

Kurata, K. 1990. Role of reflection in light transmissivity of greenhouses. Agricultural and Forest Meteorology 52:319-331.

Kuuluvainen, T. and T. Pukkala. 1987. Effect of crown and tree distribution on the spatial distribution of shade. Agricultural and Forest Meteorology 40:215-231.

Lafleur, P. and P. Adams. 1986. The radiation budget of a subarctic woodland canopy. Arctic 39:172-176.

Lang, A. R. G. 1986. Estimation of leaf area index from transmission of direct sunlight in discontinuous canopies. Agricultural and Forest Meteorology 37:229-243.

Lang, A. R. G. 1987. Simplified estimate of leaf area index from transmittance of the sun's beam. Agricultural and Forest Meteorology 41:179-186.

Lasko, A. N. and R. C. Musselman. 1976. Effects of cloudiness on interior diffuse light in apple trees. Journal of the American Society for Horticultural Science 101:642-644.

Lean, J. 1989. Contribution of ultraviolet irradiance variations to changes in the sun's total irradiance. Science 244:197-200.

Lee, D. W. and R. Graham. 1986. Leaf optical properties of rainforest sun and extreme shade plants. American Journal of Botany 73:1100-1108.

Lee, R. and A. Fraser. 1990. The light at the end of the rainbow. New Scientist 127:40-44.

Lee, W. G., I. J. Hodgkinson, and P. N. Johnson. 1990. A test for ultraviolet reflectance from fleshy fruits of New Zealand plant species. New Zealand Journal of Botany 28:21-24.

Legaz, M. E., C. Vicente, C. Ascaso, E. C. Pereira, and L. X. Filho. 1986. Pigment analysis of sun and shade populations of Cladonia verticillaris. Biochemical Systematics and Ecology 14:575-582.

Le Gouallec, J. L., G. Cornic, and P. Blanc. 1990. Relations between sunfleck sequences and photoinhibition of photosynthesis in a tropical rain forest understory herb. American Journal of Botany 77:999-1006.

Lei, T. T. and M. J. Lechowicz. 1990. Shade adaptation and shade tolerance in saplings of three Acer species from eastern North America. Oecologia 84:224-228.

Leuning, R. and K. W. Cremer. 1988. Leaf temperatures during radiation frost. I. Observations. Agricultural and Forest Meteorology 42:121-133.

Lieth, J. H. and J. F. Reynolds. 1984. A model of canopy irradiance in relation to changing leaf area in a phytotron-grown snap bean (Phaseolus vulgaris L.) crop. International Journal of Biometeorology 28:61-72.

Lillesaeter, O. 1982. Spectral reflectance of partly transmitting leaves: Laboratory measurements and mathematical modeling. Remote Sensing of Environment 12:247-254.

Lipscomb, M. V. and E. T. Nilsen. 1990. Environmental and physiological factors influencing the natural distribution of evergreen and deciduous ericaceous shrubs on northeast and southwest slopes of the southern Appalachian Mountains. I. Irradiance tolerance. American Journal of Botany 77:108-115.

Lowman, M. D. 1986. Light interception and its relation to structural differences in three Australian rainforest canopies. Australian Journal of Ecology 11:163-170.

Mandoli, D. F. and W. R. Briggs. 1982. The photoperceptive sites and the function of tissue light-piping in photomorphogenesis of etiolated oat seedlings. Plant, Cell and Environment 5:137-145.

Mann, J. E., G. L. Curry, D. W. DeMichele, and D. N. Baker. 1980. Light penetration in a row-crop with random plant spacing. Agronomy Journal 72:131-142.

Mann, J. E., G. L. Curry, and P. J. H. Sharpe. 1979. Light interception by isolated plants. Agricultural Meteorology 20:205-214.

Marshall, B. and P. V. Biscoe. 1980. A model for C3 leaves describing the dependence of net photosynthesis on irradiance. II. Application to the analysis of flag leaf photosynthesis. Journal of Experimental Botany 31:41-48.

Marshall, B. and P. V. Biscoe. 1980. A model for C3 leaves describing the dependence of net photosynthesis on irradiance. I. Derivation. Journal of Experimental Botany 31:29-39.

Matthews, R. B., R. A. Saffell, and G. S. Campbell. 1987. An instrument to measure light distribution in row crops. Agricultural and Forest Meteorology 39:177-184.

McCaughey, J. H. 1978. Estimation of net radiation for a coniferous forest, and the effects of logging on net radiation and the reflection coefficient. Canadian Journal of Forest Research 8:450-455.

McCaughey, J. H. 1987. The albedo of a mature mixed forest and a clear-cut site at Petawawa, Ontario. Agricultural and Forest Meteorology 40:251-263.

McCree, K. J. and M. E. Keener. 1974. Effect of atmospheric turbidity on the photosynthetic rates of leaves. Agricultural Meteorology 13:349-357.

McMillen, G. G. and J. H. Clendon. 1979. Leaf angle an adaptive feature of sun and shade leaves. Botanical Gazette 140:437-442.

Medina, E., M. Sobrado, and R. Herrera. 1978. Significance of leaf orientation for leaf temperature in an Amazonian sclerophyll vegetation. Radiation and Environmental Biophysics 15:131-140.

Meinzer, F. C. 1982. The effect of light on stomatal control of gas exchange in Douglas fir (Pseudotsuga menziesii) saplings. Oecologia 54:270-274.

Menzel, C. M. 1986. Plant water relations in lychee: Effect of solar radiation interception on leaf conductance and leaf water potential. Agricultural and Forest Meteorology 37:259-266.

Methy, M., P. Alpert, and J. Roy. 1990. Effects of light quality and quantity on growth of the clonal plant Eichlornia crassipes . Oecologia 84:265-271.

Miller, E. E. and J. M. Norman. 1971. A sunfleck theory for plant canopies. II. Penumbra effect: intensity distributions along sunfleck segments. Agronomy Journal 63:739-743.

Mitchell, P. L. and F. I. Woodward. 1987. Instrument for measuring temperature, photosynthetically active radiation and daylength, and its use in the measurement of daylength and temperature in coppice. Journal of Applied Ecology 24:239-249.

Mohr, H., H. Drumm, R. Schmidt, and B. Steinitz. 1979. The effect of light pretreatments on phytochrome-mediated induction of anthocyanin and of phenylalanine ammonia-lyase. Planta 146:369-376.

Monteith, J. L. 1963. Light distribution and photosynthesis in field crops. Annals of Botany 29:17-37.

Mor, Y. and N. Zieslin. 1990. UV induced blackening of rose petals. Environmental and Experimental Botany 30:455-462.

Moses, P. B. and N. -H. Chua. 1988. Light switches for plant genes. Scientific American 258:88-93.

Myneni, R. B., G. Asrar, E. T. Kanemasu, D. J. Lawlor, and I. Impens. 1986. Canopy architecture, irradiance distribution on leaf surfaces and consequent photosynthetic efficiencies in heterogeneous plant canopies. Part I. Theoretical considerations. Agricultural and Forest Meteorology 37:189-204.

Myneni, R. B., G. Asrar, E. T. Kanemasu, D. J. Lawlor, and I. Impens. 1986. Canopy architecture, irradiance distribution on leaf surfaces and consequent photosynthetic efficiencies in heterogeneous plant canopies. Part II. Results and discussion. Agricultural and Forest Meteorology 37:205.

Neufeld, H. S. 1986. Ecophysiological implications of tree architecture for two cypress taxa, Taxodium distichum (L.) Rich. and T. ascendens Brongn. Bulletin of the Torrey Botanical Club 113:118-124.

Neufeld, H. S., F. C. Meinzer, C. S. Wisdom, M. R. Sharifi, Rundel, P.W., M. S. Neufeld, Y. Goldring, and G. L. Cunningham. 1988. Canopy architecture of Larrea tridentata (DC.) Cov., a desert shrub: foliage orientation and direct beam radiation interception. Oecologia 75:54-60.

Nijskens, J., J. Deltour, S. Coutisse, and A. Nisen. 1985. Radiation transfer through covering materials, solar and thermal screens of greenhouses. Agricultural and Forest Meteorology 35:229-242.

Niklas, K. J. 1989. The effect of leaf-lobing on the interception of direct solar radiation. Oecologia 80:59-.

Nobel, P. S. 1982. Orientation, PAR interception, and nocturnal acidity increases for terminal cladodes of a widely cultivated cactus, Opuntia ficus-indica. American Journal of Botany 69:1462-1469.

Nordtug, T. and T. B. Melo. 1988. Diurnal variations in natural light conditions at summer time in arctic and subarctic areas in relation to light detection in insects. Holarctic Ecology 11:202-209.

Norman, J. M. and P. G. Jarvis. 1975. Photosynthesis in Sitka spruce (Picea sitchensis (Bong.) Carr.). V. Radiation penetration theory and a test case. Journal of Applied Ecology 12:839-878.

Oberbauer, S. F. and B. R. Strain. 1986. Effect of canopy position and irradiance on the leaf physiology and morphology of Pentaclethra macroloba (Mimosaceae). American Journal of Botany 73:409-416.

O'Rourke, P. A. and W. H. Terjung. 1981. Modelling of influence of cloud amounts and types on leaf net photosynthetic rates inside a mature canopy. Photosynthetica 15:317-329.

Orth, A. B., A. H. Teramura, and H. D. Sisler. 1990. Effects of ultraviolet-B radiation on fungal disease development in Cucumis sativus. American Journal of Botany 77:1188-1192.

Osonubi, O. and W. J. Davies. 1980. The influence of water stress on the photosynthetic performance and behaviour of tree seedlings subjected to variation in temperature and irradiance. Oecologia 45:3-10.

Overdieck, D. 1978. CO2 gas exchange and transpiration of sun- and shade-leaves under different spectral irradiation qualities (Fagus sylvatica L.). Berichte der Deutschen Botanischen Gesellschaft 91:633-644.

Oya, V. M. and A. Kh Laisk. 1976. Adaptation of the photosynthesis apparatus to the light profile in the leaf. Fiziologiya Rastenii 23:445-451.

Pallardy, S. G. and T. T. Kozlowski. 1979. Stomatal response of Populus clones to light intensity and vapor pressure deficit. Plant Physiology 64:112-114.

Palmer, J. W. 1977. Diurnal light interception and a computer model of light interception by hedgerow apple orchards. Journal of Applied Ecology 14:601-414.

Palmer, J. W. and J. E. Jackson. 1977. Seasonal light interception and canopy development in hedgerow and bed system apple orchards. Journal of Applied Ecology 14:539-549.

Panagopoulos, I., J. F. Bornman, and L. O. Björn. 1990. Effects of ultraviolet radiation and visible light on growth, fluorescence induction, ultraweak luminescence and peroxidase acitivity in sugar beet plants. Journal of Photochemistry and Photobiology 8:73-77.

Pass, R. G. and D. E. Hartley. 1979. Net photosynthesis of three foliage plants under low irradiation levels. Journal of the American Society for Horticultural Science 104:745-748.

Pech, G. 1986. Mobile sampling of solar radiation under conifers. Agricultural and Forest Meteorology 37:15-28.

Pereira, A. R., E. C. Machado, and Paes de Camargo. 1982. Solar radiation regime in three cassava (Manihot esculenta Crantz) canopies. Agricultural Meteorology 26:1-10.

Pierce, L. L. and S. W. Running. 1988. Rapid estimation of coniferous forest leaf area index using a portable integrating radiometer. Ecology 69:1762-1767.

Popma, J. and F. Bongers. 1988. The effect of canopy gaps on growth and morphology of seedlings of rain forest species. Oecologia 75:625-632.

Pukacki, P., M. Giertych, and W. Chalupka. 1980. Light filtering function of bud scales in woody plants. Planta 150:132-133.

Raschke, K., W. F. Hanebuth, and G. D. Farquhar. 1978. Relationship between stomatal conductance and light intensity in leaves of Zea mays L., derived from experiments using the mesophyll as shade. Planta 139:73-77.

Rawson, H. M., R. L. Dunstone, M. J. Long, and J. E. Begg. 1984. Canopy development, light interception and seed production in sunflower as influenced by temperature and radiation. Australian Journal of Plant Physiology 11:255-265.

Rees, D. J. 1986. The effects of population density, row spacing and intercropping on the interception and utilization of solar radiation by Sorghum bicolor and Vigna unguiculata in semi-arid conditions in Botswana. Journal of Applied Ecology 23:917-928.

Revfeim, K. J. A. 1979. Maximisation of global daily radiation on sloping surfaces. New Zealand Journal of Science 22:293-297.

Rice, S. A. and F. A. Bazzaz. 1989. Growth consequences of plasticity of plant traits in response to light conditions. Oecologia 78:508-512.

Richardson, S. G. and F. B. Salisbury. 1977. Plant responses to the light penetrating snow. Ecology 58:1152-1158.

Roberts, D. W. A. 1984. The effect of light on development of the rosette growth habit of winter wheat. Canadian Journal of Botany 62:818-822.

Rodskjer, N. and L. Dahlstedt. 1977. Measurements of solar radiation in winter wheat. Swedish Journal of Agricultural Research 7:85-88.

Ross, J. 1975. Radiative transfer in plant communities. In J.L. Monteith, editor. Vegetation and atmosphere, volume 1. Principles. Academic Press, New York, New York, USA.

Ross, J. 1981. The radiation regime and architecture of plant stands. Dr. W. Junk, The Hague, The Netherlands.

Rossotti, H. 1985. Colour. Princeton University Press, Princeton, New Jersey, USA.

Rowland-Bamford, A. J., C. Nordenbrock, J. T. Baker, G. Bowes, and L. H. Jr Allen. 1990. Changes in stomatal density in rice grown under various CO2 regimes with natural solar irradiance. Environmental and Experimental Botany 30:175-180.

Rupert, C. S. 1974. Dosimetric concepts in photobiology. Photochemistry and Photobiology 20:203-212.

Sale, P. J. M. 1977. Net carbon exchange rates of field-grown crops in relation to irradiance and dry weight accumulation. Australian Journal of Plant Physiology 4:555-569.

Salminen, R., P. Hari, E. Korpilahti, M. Kotiranta, and R. Sievanen. 1983. A measuring system for estimating the frequency distribution of irradiance within plant canopies. Journal of Applied Ecology 20:887-895.

Salminen, R., T. Nilson, P. Hari, L. Kaipianen, and J. Ross. 1983. A comparison of different methods for measuring the canopy light regime. The Journal of Applied Ecology 20:897-904.

Satterlund, D. R. 1979. An improved equation for estimating long-wave radiation from the atmosphere. Water Resources Research 15:1649-1650.

Schimpf, D. J. and S. D. Flint. 1985. Light and germination: Alternatives in lamps, filters and seeds. The American Biology Teacher 47:410-411.

Schwank, O., H. Blum, and J. Nosberger. 1986. The influence of irradiance distribution on the growth of white clover (Trifolium repens L.) in differently managed canopies of permanent grassland. Annals of Botany 57:273-281.

Sheehy, J. E. and L. C. Chapas. 1976. The measurement and distribution of irradiance in clear and overcast conditions in four temperate forage grass canopies. Journal of Applied Ecology 13:831-840.

Sheehy, J. E. and D. Cook. 1977. Irradiance distribution and carbon-dioxide flux in forage grass canopies. Annals of Botany 41:1017-1029.

Sheriff, D. W. and M. M. Ludlow. 1985. Diaheliotropic responses of leaves of Macroptillium atropurpureum cv. Sirato . Australian Journal of Plant Physiology 12:151-171.

Shibayama, M. and C. L. Wiegand. 1985. View azimuth and zenith, and solar angle effects on wheat canopy reflectance. Remote Sensing of Environment 18:91-103.

Sionit, N. and D. T. Patterson. 1985. Responses of C4 grasses to atmospheric CO2 enrichment. 1. Effect of irradiance. Oecologia 65:30-34.

Smith, H., J. J. Casal, and G. M. Jackson. 1990. Reflection signals and the perception by phytochrome of the proximity of neighbouring vegetation. Plant, Cell and Environment 13:73-78.

Smith, J. A. and J. K. Berry. 1979. Optical diffraction analysis for estimating foliage angle distribution in grassland canopies. Australian Journal of Botany 27:123-133.

Smith, M. and C. E. Martin. 1987. Photosynthetic responses to irradiance in three forest understory species of the C4 genus Muhlenbergia. Botanical Gazette 148:275-282.

Spitters, C. J. T. 1986. Separating the diffuse and direct component of global radiation and its implications for modeling canopy photosynthesis. Part II. Calculation of canopy photosynthesis. Agricultural and Forest Meteorology 38:231-242.

Spitters, C. J. T., H. A. J. M. Toussaint, and J. Goudriaan. 1986. Separating the diffuse and direct component of global radiation and its implications for modeling canopy photosynthesis. Part I. Components of incoming radiation. Agricultural and Forest Meteorology 38:217-229.

Stathers, R. J. and W. G. Bailey. 1986. Energy receipt and partitioning in a ginseng shade canopy and mulch environment. Agricultural and Forest Meteorology 37:1-14.

Stoner, W. A., P. C. Miller, and P. M. Miller. 1978. A test of a model of irradiance within vegetation canopies at northern latitudes. Arctic and Alpine Research 10:761-767.

Stoutjesdijk, P. 1974. The open shade, an interesting microclimate. Acta Botanica Neerlandica 23:125-130.

Stoutjesdijk, Ph. 1972. Spectral transmission curves of some types of leaf canopies with a note on seed germination. Acta Botanica Neerlandica 21:185-191.

Swift, L. W. Jr. 1976. Algorithm for solar radiation on mountain slopes. Water Resources Research 12:108-112.

Syverstsen, J. P. and G. L. Cunningham. 1979. The effects of irradiating adaxial or abaxial leaf surface on the rate of net photosynthesis of Perezia nana and Helianthus annuus . Photosynthetica 13:287-293.

Teramura, A. H., J. H. Sullivan, and L. H. Ziska. 1990. Interaction of elevated ultraviolet-B and CO2 on productivity and photosynthetic characterisitics in wheat, rice, and soybean. Plant Physiology 94:470-475.

Thompson, K. 1989. A comparative study of germination responses to high irradiance light. Annals of Botany 63:159-162.

Thompson, L. and J. L. Harper. 1988. The effect of grasses on the quality of transmitted radiation and its influence on the growth of white clover Trifolium repens. Oecologia 75:343-347.

Thorpe, M. R. 1978. Net radiation and transpiration of apple trees in rows. Agricultural Meteorology 19:41-57.

Torssell, B. W. R. and H. G. McPherson. 1977. An improved model for simulating the penetration, propagation and absorption of radiation within plant canopies. Australian Journal of Ecology 2:245-256.

Travis, A. J. and T. A. Mansfield. 1981. Light saturation of stomatal opening on the adaxial and abaxial epidermis of Commelina communis. Journal of Experimental Botany 32:1169-1179.

Tucker, C. J. 1977. Spectral estimation of grass canopy variables. Remote Sensing of Environment 6:11-26.

Tuller, S. E. and M. J. Peterson. 1988. The solar radiation environment of greenhouse-grown Douglas-fir seedlings. Agricultural and Forest Meteorology 44:49-65.

Vazquez-Yanes, C. 1980. Light quality and seed germination in Cecropia obtusifolia and Piper auritum from a tropical rain forest in Mexico. Oyton 38:33-35.

Virgin, H. I. 1990. The light-induced unrolling of the grass leaf - A study of polarity, light-piping and stimulus transmission. Physiologia Plantarum 80:143-147.

Virgin, H. I. 1989. An analysis of the light-induced unrolling of the grass leaf. Physiologia Plantarum 75:295-298.

Vos, J. and P. J. Oyarzun. 1987. Photosynthesis and stomatal conductance of potato leaves - effects of leaf age, irradiance, and leaf water potential. Photosynthesis Research 11:253-264.

Wald, G. 1959. Life and light. Scientific American 201:92-112.

Wall, G. W. and E. T. Kanemasu. 1990. Carbon dioxide exchange rates in wheat canopies. Part I. Influence of canopy geometry on trends in leaf area index, light interception and instantaneous exchange rates. Agricultural and Forest Meteorology 49:81-102.

Wallace, L. L. and E. L. Dunn. 1980. Comparative photosynthesis of three gap phase successional tree species. Oecologia 45:331-340.

Walton, D. W. H. 1982. Instruments for measuring biological microclimate for terrestrial habitats in polar and high alpine regions: A review. Arctic and Alpine Research 14:275-286.

Warren Wilson, J. 1981. Analysis of light interception by single plants. Annals of Botany 48:501-505.

Warren Wilson, J. 1981. Analysis of growth, photosynthesis and light interception for single plants and stands. Annals of Botany 48:507-512.

Weiss, A. and J. M. Norman. 1985. Partitioning solar radiation into direct and diffuse, visible and near-infrared components. Agricultural and Forest Meteorology 34:205-214.

Wild, A. 1979. Physiology of photosynthesis in higher plants. The adaptation to light intensity and light quality. Berichte der Deutschen Botanischen Gessellschaft 92:341-364.

Williams, M. A. and R. B. Austin. 1977. Short note: an instrument for measuring the transmission of short wave radiation by crop canopies. Journal of Applied Ecology 14:987-992.

Wilson, D. R., C. J. Fernandez, and K. J. McCree. 1978. CO2 exchange of subterranean clover in variable light environments. Crop Science 18:19-22.

Woodhouse, R. M., J. G. Williams, and P. S. Nobel. 1980. Leaf orientation, radiation interception, and nocturnal acidity increases by the CAM plant Agave deserti (Agavaceae). American Journal of Botany 67:1179-1185.

Wright, C. J. and P. D. Waister. 1984. Light interception and fruiting cane architecture in the red raspberry grown under annual and biennial management systems. Journal of Horticultural Science 59:395-402.

Yamaguchi, T. and D. J. C. Friend. 1979. Effect of leaf age and irradiance on photosynthesis of Coffea arabica. Photosynthetica 13:271-278.

Young, E. and J. W. Hanover. 1977. Effects of quality, intensity, and duration of light breaks during a long night on dormancy in blue spruce (Picea pungens Engelm.) seedlings. Plant Physiology 60:271-273.

Yun, J. I. and S. E. Taylor. 1986. Adaptive implications of leaf thickness for sun- and shade-grown Abutilon theophrasti . Ecology 67:1314-1318.

Zangerl, A. R. and F. A. Bazzaz. 1984. The response of plants to elevated CO2. II. Competitive interactions among annual plants under varying light and nutrients. Oecologia 62:412-417.

Zeigler, E. and P. K. Hepler. 1977. Light and stomatal function: blue light stimulates swelling of guard cell protoplasts. Science 196:887-888.