Stomatal conductance of some grapevines growing in the field under a Mediterranean environment

Abstract

A semi-empirical model of stomatal conductance was used to analyse porometer measurements on different grapevine cultivars under field conditions. Stomatal conductance was expressed as a function of quantum flux density, water vapour deficit, air temperature and leaf water potential.Where possible, the parameters describing the partial functions were estimated from field data and provide physiological insights into the transpiration process. They indicated differential stomatal sensitivity to air humidity in the various cultivars, a characteristic which could be related to their geographical origins.

Stomatal response of Quercus pyrenaica Willd to environmental factors in two sites differing in their annual rainfall (Sierra de Gata, Spain)

“…The type of response obtained for temperature, in the form of a dome-shaped curve, is closer to those described by Jarvis (1976), Winkel and Rambal (1990), Sala (1992) and Foster (1992) than to those published by Chambers et al (1985), where they have a more pronounced maximum, with optimum temperatures from 25 to 27 °C for the three oak species studied. In our case, the optimum temperature observed was somewhat low and possibly not corresponding to reality because of the interaction of temperature and VPD on conductance (Jarvis, 1976 Jarvis (1976) and Winkel and Rambal (1990).…”

“…In our case, the optimum temperature observed was somewhat low and possibly not corresponding to reality because of the interaction of temperature and VPD on conductance (Jarvis, 1976 Jarvis (1976) and Winkel and Rambal (1990). However, Foster (1992) (FG), and a more optimistic one at the wet site (NV).…”

“…Although water relations in sclerophytic oak species have been well documented (Rambal and Leterme, 1987;Salleo and Lo Gullo, 1990;Oliveira et al, 1992;Rambal, 1992;Sala, 1992;Sala and Tenhunen, 1994), there have been fewer studies on deciduous oak species (Chambers et al, 1985; Kubiske and Abrams, 1992;Epron and Dreyer, 1993 (Acherar and Rambal, 1992); this could be related more to environmental conditions than to the actual physiology of the tree (Gallego et al, 1994 (1990)(1991)(1992) The semi-empirical model of stomatal conductance used has been described by Jarvis (1976), Winkel and Rambal (1990) and Jones (1992). This model is based on known relationships between stomatal conductance (g s , mmol m -2 s -1 ) and PAR (μmol m -2 s -1 ), VPD (KPa), T a (°C) and leaf water potential (ψ MPa).…”

“…Among the environmental factors affecting stomatal opening, solar radiation, soil water availability, atmospheric vapour pressure deficit and temperature are known to be important (Schulze, 1986;Winkel and Rambal, 1990;Turner, 1991).…”

“…Stomatal behaviour with respect to humidity may be linear or nonlinear (Jarvis, 1976;Winkel and Rambal, 1990) Jarvis, 1976;Chambers et al, 1985;Winkel and Rambal, 1990;Jones, 1992 (Winkel and Rambal, 1993;Moreno et al, 1996), root water status (Meinzer, 1993) or the proportion of roots in dry soil (Turner, 1991) should be taken into account.…”