Seasonal and diurnal measurements of leaf water potential, stomatal conductance, and stem sap flow were made in adult plants of Arbutus unedo, Cistus monspeliensis, Erica arborea, Myrtus communis, Phillyrea latifolia and Quercus ilex growing under field conditions in coastal Tuscany for two years. Values of pre‐dawn leaf water potentials were higher than‐1.5 MPa for all species during most of the year. Minima of less than‐8 MPa were reached for E. arborea and C. monspeliensis in the summer, when those of P. latifolia and Q. ilex were‐5.0 and‐5.2 MPa, respectively. A high diurnal difference in leaf water potential was maintained in P. latifolia throughout the study period, including summer. During summer months, diurnal differences in leaf water potential were smaller in Q. ilex, M. communis and A, unedo than in P. latifolia, and virtually zero in E. arborea and C. monspeliensis. Stomata were closed in all species at the peak of stress. C. monspeliensis showed the highest stomatal conductance in the months prior to the onset of the drought period. Sap flow per unit leaf area of C. monspeliensis was two to three fold higher than those of M. communis and P. latifolia during periods of adequate soil moisture availability.
Seasonal changes in the water relations of Mediterranean co-occuring woody species
GUCCI, RICCARDO;MASSAI, ROSSANO;
1999-01-01
Abstract
Seasonal and diurnal measurements of leaf water potential, stomatal conductance, and stem sap flow were made in adult plants of Arbutus unedo, Cistus monspeliensis, Erica arborea, Myrtus communis, Phillyrea latifolia and Quercus ilex growing under field conditions in coastal Tuscany for two years. Values of pre‐dawn leaf water potentials were higher than‐1.5 MPa for all species during most of the year. Minima of less than‐8 MPa were reached for E. arborea and C. monspeliensis in the summer, when those of P. latifolia and Q. ilex were‐5.0 and‐5.2 MPa, respectively. A high diurnal difference in leaf water potential was maintained in P. latifolia throughout the study period, including summer. During summer months, diurnal differences in leaf water potential were smaller in Q. ilex, M. communis and A, unedo than in P. latifolia, and virtually zero in E. arborea and C. monspeliensis. Stomata were closed in all species at the peak of stress. C. monspeliensis showed the highest stomatal conductance in the months prior to the onset of the drought period. Sap flow per unit leaf area of C. monspeliensis was two to three fold higher than those of M. communis and P. latifolia during periods of adequate soil moisture availability.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
