Photosynthetica 2003, 41(3):343-347 | DOI: 10.1023/B:PHOT.0000015457.92479.eb
A Test of Gas Exchange Measurements on Excised Canopy Branches of Ten Tropical Tree Species
- 1 Department of Botany, University of Florida, Gainesville, USA
We studied gas exchange of leaves on branches that had been cut and then re-cut under water to assess the utility of measuring gas exchange on leaves of excised canopy branches. There was large variation between species in their ability to photosynthesize following excision. Some species maintained up to 86.5% of intact photosynthetic rate 60 min after excision, whereas other species dropped below 40% of intact photosynthetic rates within 3 min. Three species showed significant reductions in maximum rates of gross photosynthetic rate (PG) on leaves of excised branches relative to intact branches. Excision significantly reduced carboxylation rates (Vcmax) in four species and electron transport (Jmax) in two species. There were also significant increases in compensation irradiance and reductions of day rates of respiration relative to intact measurements. While gas exchange on excised branches can provide useful measures for canopy species, responses of individual species to branch excision need to be taken into account. Measurements on pre-screened species allow a greater understanding of canopy photosynthesis of large trees when canopy access is not an option.
Additional key words: canopy physiology; CO2 response curve; Panama; potometer; species differences in photosynthetic characteristics; specific leaf area; stomatal conductance; tropical forest
Published: September 1, 2003 Show citation
References
- Boari, F., Malone, M.: Wound-induced hydraulic signals: Survey of occurrence in a range of species. - J. exp. Bot. 44: 741-746, 1993.
Go to original source... - Caemmerer, S. von, Farquhar, G.D.: Some relationships between the biochemistry of photosynthesis and the gas exchange of leaves. - Planta 153: 376-387, 1981.
Go to original source... - Croat, T.B.: Flora of Barro Colorado Island. - Stanford University Press, Stanford 1978.
- Dang, Q.-L., Margolis, H.A., Coyea, M.R., Sy, M., Collatz, G.J.: Regulation of branch-level gas exchange of boreal trees: roles of shoot water potential and vapor pressure difference. - Tree Physiol. 17: 521-535, 1997.
Go to original source... - Gerrish, G.: Changing photosynthetic capacity during leaf ontogeny in juvenile and mature Metrosideros polymorpha trees. - Pacific Sci. 46: 315-324, 1992.
- Ginn, S.E., Seiler, J.R., Cazell, B.H., Kreh, R.E.: Physiological and growth responses of eight-year-old pine stands to thinning. - Forest Sci. 37: 1030-1040, 1991.
- Koyama, H.: Photosynthetic rates in lowland rain forest trees of peninsular Malaysia. - Jap. J. Ecol. 31: 361-369, 1981.
- Kramer, P.J., Kozlowski, T.T.: Physiology of Woody Plants. - Academic Press, New York 1979.
- Lambers, H., Chapin, F.S., III, Pons, T.L.:Plant Physiological Ecology. - Springer-Verlag, New York 1998.
Go to original source... - Mulkey, S.S., Kitajima, K., Wright, S.J.: Plant physiological ecology of tropical forest canopies. - Trends Ecol. Evolut. 11: 408-412, 1996.
Go to original source... - Reich, P.B., Ellsworth, D.S., Uhl, C.: Leaf carbon and nutrient assimilation and conservation in species of differing successional status in an oligiotrophic Amazonian forest. - Funct. Ecol. 9: 65-76, 1995.
Go to original source... - Reich, P.B., Walters, M.B., Ellsworth, D.S., Vose, J.M., Volin, J.L., Greshan, C.A., Bowman, W.D.: Relationships of leaf dark respiration to leaf nitrogen, specific leaf area and leaf life-span: a test across biomes and functional groups. - Oecologia 114: 471-482, 1998.
Go to original source... - Running, S.W., Coughlan, J.C.: A general model for forest ecosystem processes for regional applications. I. Hydrologic balance, canopy gas exchange and primary production processes. - Ecol. Model. 42: 125-154, 1988.
Go to original source... - Samuelson, L.J.: Influence of intensive culture on leaf net photosynthesis and growth of sweetgum and loblolly pine seedlings. - Forest Sci. 44: 308-316, 1998.
- Santiago, L.S.: Leaf Traits of Canopy Trees on a Precipitation Gradient in Panama: Integrating Plant Physiological Ecology and Ecosystem Science. - Ph.D. Dissertation. Department of Botany, University of Florida, Gainesville 2003.
- Sims, D.A., Pearcy, R.W.: Photosynthesis and respiration in Alocasia macrorrhiza following transfers to high and low light. - Oecologia 86: 447-453, 1991.
Go to original source... - Sperry, J.S., Alder, N.N., Eastlack, S.E.: The effect of reduced hydraulic conductance on stomatal conductance and xylem cavitation. - J. exp. Bot. 44: 1075-1082, 1993.
Go to original source... - Stahlberg, R., Cosgrove, D.J.: Comparison of electric and growth responses to excision in cucumber and pea seedlings. II. Long-distance effects are caused by the release of xylem pressure. - Plant Cell Environ. 18: 33-41, 1995.
Go to original source... - Tardieu, F., Davies, W.J.: Integration of hydraulic and chemical signalling in the control of stomatal conductance and water status of droughted plants: opinion. - Plant Cell Environ. 16: 341-349, 1993.
Go to original source... - Williams, M., Rastetter, E.B., Fernandes, D.N., Goulden, M.L., Wofsy, S.C., Shaver, G.R., Melillo, J.M., Munger, J.W., Fan, S.-M., Nadelhoffer, K.J.: Modelling the soil-plant atmosphere continuum in a Quercus-Acer at Harvard Forest: the regulation of stomatal conductance by light, nitrogen and soil/plant hydraulic properties. - Plant Cell Environ. 19: 911-927, 1996.
Go to original source... - Williamson, V.G., Milburn, J.A.: Cavitation events in cut stems kept in water: implications for cut flower senescence. - Sci. Horticult. 64: 219-232, 1995.
Go to original source... - Zhang, J., Davies, W.J.: Changes in the concentration of ABA in xylem sap as a function of changing soil water status can account for changes in leaf conductance and growth. - Plant Cell Environ. 13: 227-285, 1990.
Go to original source...




