Summary
At constant cladode temperature the stomatal resistance of O. inermis increased when the cladode-air vapor pressure difference was increased and stomatal resistance decreased when the cladode-air vapor pressure difference was lowered. Net CO2 fixation in the dark was very responsive to these humidity dependent changes in stomatal resistance. Net CO2 fixation and stomatal resistance in the light did not respond to changes in cladode-air vapor pressure differences in the light under the conditions tested. When temperature response functions for dark CO2 fixation were examined at constant ambient humidity, the reduction in dark CO2 fixation at higher temperatures was largely due to stomatal closure in response to the increased vapor pressure difference. The water requirement for net CO2 fixation in the dark at typical nocturnal vapor pressure differences was about 10 times lower than that of net CO2 fixation in the light at vapor pressure differences typical of the late afternoon. The role of the stomatal responses to humidity in determining the patterns and rates of net CO2 exchange in the light or dark, and its possible ecological significance is discussed.
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References
Conde, L.F., Kramer, P.J.: The effect of vapor pressure deficit on diffusion resitance on Opuntia compressa. Canad. J. Bot. 53, 2923–2926 (1975)
Crews, C.E., Vines, H.M., Black, C.C.: Post illumination burst of carbon dioxide in crassulacean acid metabolism plants. Plant Physiol. 55, 652–657 (1974)
Hanscomb III, Z., Ting, I.P.: Irrigation magnifies CAM-photosynthesis in Opuntia basilaris (Cactaceae). Oecologia 33, 1–15 (1978)
Neales, T.F.: The effect of night temperature on CO2 assimilation, transpiration and water use efficiency in Agave americana. Australian J. Biol. Sci., 26, 705–714 (1973)
Nobel, P.S.: Water relations of a desert CAM plant, Agave deserti. Plant Physiol. 58, 576–582 (1976)
Nobel, P.S.: Water relations and photosynthesis of a barrel cactus, Ferrocactus acanthodes in the Colorado desert. Oecologia 27, 117–133 (1977)
Osmond, C.B.: Crassulacean acid metabolism: a curiosity in context. Ann. Rev. Plant Physiol. 29, 379–414 (1978)
Osmond, C.B., Björkman, O.: Pathways of CO2 fixation in the CAM plant Kalanchoe daigremontiana II. Effects of O2 and CO2 concentration on light and dark CO2 fixation. Australian J. Plant Physiol. 2, 155–162 (1975)
Osmond, C.B., Nott, D.L., Firth, P.M.: Carbon assimilation patterns and growth of the introduced CAM plant Opuntia inermis in Eastern Australia. Oecologia (Berl.) 40, 331–350 (1979)
Schulze, E.-D., Lange, O.L., Bushbom, U., Kappen, L., Evenari, M.: Stomatal responses to changes in humidity in plants growing in the desert. Planta 108, 259–270 (1972)
Szarek, S.R., Johnson, H.B., Ting, I.P.: Drought adaptation in Opuntia basilaris. Significance of recycling carbon through crassulacean acid metabolism. Plant Physiol. 52, 539–541 (1973)
Szarek, S.R., Ting, I.P.: Photosynthetic efficiency of CAM plants in relation to C3 and C4 plants. In: Environmental and biological control of photosynthesis (Marcelle, R., ed.). pp. 289–297. Amsterdam: Junk 1975
Ting, I.P. Johnson, H.B., Szarek, S.R.: Net of CO2 fixation in crassulacean acid metabolism plants. In: Net carbon dioxide assimilation in higher plants Black, C.C., (ed.). pp. 26–53. Mobile: South Sect. Am. Soc. Plant Physiol./Cotton Inc., 1972
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Osmond, C.B., Ludlow, M.M., Davis, R. et al. Stomatal responses to humidity in Opuntia inermis in relation to control of CO2 and H2O exchange patterns. Oecologia 41, 65–76 (1979). https://doi.org/10.1007/BF00344837
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DOI: https://doi.org/10.1007/BF00344837