The Interpretation of the Variations in Leaf Water Potential and Stomatal Conductance Found in Canopies in the Field

Attempts to correlate values of stomatal conductance and leaf water potential with particular environmental variables in the field are generally of only limited success because they are simultaneously affected by a number of environmental variables. For example, correlations between leaf water potential and either flux of radiant energy or vapour pressure deficit show a diurnal hysteresis which leads to a scatter diagram if many values are plotted. However, a simple model may be adequate to relate leaf water potential to the flow of water through the plant. The stomatal conductance of illuminated leaves is a function of current levels of temperature, vapour pressure deficit, leaf water potential (really turgor pressure) and ambient CO $_2$ concentration. Consequently, when plotted against any one of these variables a scatter diagram results. Physiological knowledge of stomatal functioning is not adequate to provide a mechanistic model linking stomatal conductance to all these variables. None the less, the parameters describing the relationships with the variables can be conveniently estimated from field data by a technique of non-linear least squares, for predictive purposes and to describe variations in response from season to season and plant to plant.

[1]  P. Jarvis,et al.  An Analytical Model for Field Measurement of Photosynthesis , 1976 .

[2]  P. G. Jarvis,et al.  Photosynthesis in Sitka Spruce (Picea sitchensis (Bong.) Carr.): VI. Response of Stomata to Temperature , 1975 .

[3]  M. R. Thorpe,et al.  Diurnal Energy, Water and CO 2 Exchanges in an Apple (Malus pumila) Orchard , 1975 .

[4]  J. Gash,et al.  The average surface resistance of a pine forest derived from Bowen ratio measurements , 1975 .

[5]  M. Kaufmann,et al.  Efficiency and regulation of water transport in some woody and herbaceous species. , 1974, Plant physiology.

[6]  N. Turner,et al.  Stomatal Behavior and Water Status of Maize, Sorghum, and Tobacco under Field Conditions: II. At Low Soil Water Potential. , 1974, Plant physiology.

[7]  Hanno Riceter.  Frictional Potential Losses and Total Water Potential in Plants: a Re-evaluation , 1973 .

[8]  J. Petty,et al.  Value Action of Bordered Pits in Conifers , 1973 .

[9]  P. Sharpe.  Adaxial and Abaxial Stomatal Resistance of Cotton in the Field1 , 1973 .

[10]  H. Neumann,et al.  DIFFUSIVE RESISTANCE, TRANSPIRATION, AND PHOTOSYNTHESIS IN SINGLE LEAVES OF CORN AND SORGHUM IN RELATION TO LEAF WATER POTENTIAL , 1973 .

[11]  G. P. Richards.  Some aspects of the water relations of Sitka spruce , 1973 .

[12]  R. E. Smart,et al.  The effect of environment and irrigation interval on leaf water potential of four horticultural species , 1973 .

[13]  K. Higgs,et al.  Water, Osmotic and Pressure Potential Relationships in Apple Leaves , 1973 .

[14]  P. G. Jarvis,et al.  A Null-Balance Diffusion Porometer Suitable for Use with Leaves of Many Shapes , 1972 .

[15]  P. Biscoe.  The Diffusion Resistance and Water Status of Leaves of Beta vulgaris , 1972 .

[16]  Anthony E. Hall,et al.  Interpreting Leaf Water Potential Measurements with a Model of the Soil‐Plant‐Atmosphere Continuum , 1972 .

[17]  M. Carr.  The internal water status of the tea plant (Camellia sinensis): Some results illustrating the use of the pressure chamber technique , 1971 .

[18]  E. B. Norum,et al.  Influence of atmospheric and soil environmental parameters on the diurnal fluctuations of leaf water status of barley , 1971 .

[19]  G. K. Hansen.  Photosynthesis, Transpiration and Diffusion Resistance in Relation to Water Potential in Leaves during Water Stress , 1971 .

[20]  B. Klepper,et al.  Diurnal pattern of water potential in woody plants. , 1968, Plant physiology.