Summary
Photosynthetic responses to incident photon flux density (400–700 nm; PPFD) was studied in a grass community consisting of Spartina patens and Distichlis spicata and a mixed community having the two grasses and a sedge, Scirpus Olneyi. Net community CO2 exchange and incident PPFD were monitored from dawn to dusk in a large open gas exchange system, and a hyperbolic light response model was fit to the data for each day. Light response curves from five growing seasons were evaluated for seasonal trends in the compensation value, initial slope, and maximum net CO2 exchange rate calculated from the model at PPFD=1670 μmol m-2s-1.
All response curves were curvilinear. Data from approximately 30% of the 113 days studied fit saturation curves which occurred primarily in spring and fall. Approximately 5% of all curves constructed required a different response curve for the morning and afternoon. These occurred during mid-summer and were interpreted to be evidence of water stress.
The compensation flux density was very high early in the growing season, but rapidly decreased and during the months June, July and August, it averaged near 100 and 120 μmol m-2s-1 in the mixed and grass communities. The initial slope and maximum net CO2 exchange rate increased from early May to maxima in July and declined thereafter. Mid-summer mean values for the mixed and grass communities respectively were 34.3±10.3 mmol mol-1 and 39.1±9.1 mmol mol-1 for the initial slope and 20.3±4.2 μmol m-2s-1 and 23.0±3.8 μmol m-2s-1 for maximum net CO2 exchange. Daytime respiration accounted for approximately 20% of maximum gross photosynthesis in both communities.
Photosynthetic efficiency, CO2 assimilated per unit total incident solar radiation, was approximately 4.1% and 4.7% at dawn or dusk and 2.3% and 2.6% at midday for the mixed and grass community. Gross photosynthesis, maximum photosynthesis plus midday respiration, accounted for 2.7% and 3.0% of total incident solar radiation in the mixed and grass communities.
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References
Baker DN, Musgrave RW (1964) Photosynthesis under field conditions. V. Further plant chamber studies of the effects of light on corn (Zea mays L.). Crop Sci 4:127–131
Bjorkman O (1971) Comparative photosynthetic CO2 exchange in higher plants. In: Hatch MD, Osmond CB, Slayter RO (eds), Photosynthesis and Photorespiration. Wiley-Interscience, New York, pp 18–32
Blum U, Seneca ED, Stroud L (1978) Photosynthesis and respiration of Spartina and Juncus salt marshes in North Carolina: some models. Estuaries 1:228–238
Brown HD (1978) A difference in N use efficiency in C3 and C4 plants and its implications in adaptation and evolution. Crop Sci 18:93–98
Cartledge O, Connor DJ (1972) Field chamber measurements of community photosynthesis. Photosynthettica 6:310–316
Cavalieri AJ, Huang AHC (1981) Accumulation of proline and glycinebetaine in Spartina alterniflora Loisel. in response to NaCl and nitrogen in the marsh. Oecologia (Berlin) 49:224–228
Christy AL, Porter CA (1982) Canopy photosynthesis and yield in soybean. In: Govindjee (ed) Photosynthesis, Vol II. Development. Carbon Metabolism and Plant Productivity. Academic Press, New York, Ch. 14, pp 499–511
DeJong TM, Drake BG (1981) seasonal patterns of plant and soil water potential in an irregularly flooded tidal marsh. Aquatic Bot 11:1–9
DeJong TM, Drake BG, Pearcey RW (1982) Gas exchange responses of Chesapeake Bay tidal marsh species under field and laboratory conditions. Oecologia (Berlin) 52:5–11
Drake BG, Read M (1981) Carbon dioxide assimilation, photosynthetic efficiency, and respiration of a chesapeake Bay salt marsh. J Ecol 69:405–423
Drake BG, Gallagher JL (1984) Osmotic potential and turgor maintenance in Spartina alterniflora Loisel. Oecologia (Berlin) 62:368–375
Ehleringer J, Pearcy RW (1983) Variations in quantum yield for CO2 uptake among C3 and C4 plants. Plant Physiol 73:555–559
Fukai S, Silsbury JH (1977) Responses of subterraneum clover communities to temperature. III. Effects of temperature on canopy photosynthesis. Aust J Plant Physiol 4:273–282
Giurgevich JR, Dunn EL (1979) Seasonal patterns of CO2 and water vapor exchange of the tall and short height forms of Spartina alterniflora in a Georgia salt marsh. Oecologia (Berlin) 43:139–156
Horie T, Udagawa T (1971) Canopy photosynthesis of sunflower plants-its measurement and modeling. Bull Nat Inst Agr Res Japan Ser A 18:1–56
Lemon ER, Wright JL (1969) Photosynthesis under field conditions. XA. Assessing sources and sinks of carbon dioxide in a corn (Zea mays L.) crop using a momentum balance approach. Agron J 61:405–411
Linthurst RA, Seneca ED (1981) Aeration, nitrogen and salinity as determinants of Spartina alterniflora Loisel. Growth response. Estuaries 4:53–63
Lorimer GH (1981) The carboxylation and oxygenation of ribulose 1,5-bisphosphate: the primary events in photosynthesis and photorespiration. Ann Rev Plant Physiol 32:349–383
Mendelssohn IA, McKee KL, Postek ML (1982) Sublethal stresses controlling Spartina alterniflora productivity. In: Gopol B, Turner RT, Wetzel RG, Whigham DF (eds) Wetlands: Ecology and Management, Nat Inst Ecol Internatl Sci Publications Jaipur, India, pp 223–242
Monsi M, Uchijima Z, Oikawa T (1973) Structure of foliage canopies and photosynthesis. Ann Rev Ecol Syst 4:301–327
Monteith JL (1978) Reassessment of maximum growth rates of C3 and C4 crops. Exp Agric 14:1–5
Osmond CB, Winter K, Ziegleri H (1982) Functional significance of different pathways of CO2 fixation in photosynthesis. Physiological Plant Ecology II. In: Lange OL, Nonel PS, Osmond CB, Ziegler H (eds) Encyclopedia of Plant Physiology, New Series, 12B, Springer Verlag, NY, pp 479–547
Pomeroy LR, Darley WM, Dunn EL, Gallagher JL, Hines EB, Whitney DM (1981) Primary production. In: Pomeroy LR, Wiegert RG (eds) The Ecology of a Salt Marsh. Ecological Studies 38: Springer-Verlag, New York, pp 39–67
Reimold RJ (1977) Mangals and salt marshes of eastern United States. In: Chapman CV (ed), Wet Coastal Ecosystems. Ecosystems of the World, Vol 1: Elsevier Sci Pub Co, New York, Ch 7, pp 157–166
Sale PJM (1974) Productivity of vegetable crops in a region of high solar input. III. Carbon balance of potato crops. Aust J Plant Physiol 1:283–296
Stanhill G, Fuchs M (1977) The relative flux density of photosynthetically active radiation. J Appl Ecol 14:317–322
Tanaka T (1972) Studies on the light curves of carbon assimilation in rice plants. The interrelation among the light curves, the plant type, and the maximizing yield of rice. Bull Nat Inst Agr Sci A- 19:1–100. Quoted in Monsi M, Uchijima Z, Oikawa T (1973) Structure of foliage canopies and photosynthesis. Ann Rev Ecol Syst 4:301–327
Turitzin SN, Drake BG (1981) The effect of a seasonal change in canopy architecture upon photosynthetic efficiency of a Chesapeake Bay tidal salt marsh. Oecologia (Berlin) 48:79–84
Turner RE (1976) Geographic variations in salt marsh macrophyte production. A Review. Contrib Mar Sci 20:47–68
Ustin SL, Pearcy RA, Bayer DA (1982) Plant water relations in a San Francisco Bay salt marsh. Bot Gaz 143:368–373
Valiela I, Teal JM (1974) Nutrient limitation in salt marsh vegetation. In: Reimold RJ, Queen WH (eds), Ecology of Halophytes. Academic Press, New York, pp 547–563
Zelitch I (1982) The close relationship between net photosynthesis and crop yield. Bioscience 32:796–802
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Drake, B.G. Light response characteristics of net CO2 exchange in brackish wetland plant communities. Oecologia 63, 263–270 (1984). https://doi.org/10.1007/BF00379887
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DOI: https://doi.org/10.1007/BF00379887