Water stress responses of seedlings of four Mediterranean oak species.

摘要: Effects of water stress on phenology, growth, stomatal activity and status were assessed from April to November 1996 in 2-year-old seedlings Quercus frainetto Ten. (Quercus conferta Kit.), pubescens Willd., macrolepis Kotschy aegilops auct.) ilex L. growing containers northern Greece. All four species developed more than 50% their total leaf area before the beginning June--an adaptation arid climates. Well-irrigated plants tended develop greater individual area, number leaves per plant, plant height root:shoot ratios water-stressed plants, but difference between treatments was not significant for any parameter species. appeared be most drought-tolerant It maintained highest smallest size increased proportion fine roots during drought. In all species, drought caused decreases conductance predawn midday potentials mid-July until end August, when lowest soil content mean daily air temperatures occurred; however, responses species-specific. Among sustained despite very low potentials, thus overcoming by means desiccation tolerance. decreased even severe occurred, thereby avoiding desication had potential a high conductance, indicating that its independent activity. least drought-resistant During it markedly reduced aperture.