Changes in petiole hydraulic properties and leaf water flow in birch and oak saplings in a CO2-enriched atmosphere.
Water relations in woody species are intimately related to xylem hydraulic properties. High CO(2) concentrations ([CO(2)]) generally decrease transpiration and stomatal conductance (g(s)), but there is little information about the effect of atmospheric [CO(2)] on xylem hydraulic properties. To determine the relationship between water flow and hydraulic structure at high [CO(2)], we investigated responses of sun and shade leaves of 4-year-old saplings of diffuse-porous Betula maximowicziana Regel and ring-porous Quercus mongolica Fisch. ex Ledeb. ssp. crispula (Blume) Menitsky grown on fertile brown forest soil or infertile volcanic ash soil and exposed to 500 micromol CO(2) mol(-1) for 3 years. Regardless of species and soil type, elevated [CO(2)] consistently decreased water flow (i.e., g(s) and leaf-specific hydraulic conductivity) and total vessel area of the petiole in sun leaves; however, it had no effect on these parameters in shade leaves, perhaps because g(s) of shade leaves was already low. Changes in water flow at elevated [CO(2)] were associated with changes in petiole hydraulic properties.
Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
Norikazu
N
Eguchi
Noriko
N
Morii
Tatsushiro
T
Ueda
Ryo
R
Funada
Kentaro
K
Takagi
Tsutom
T
Hiura
Kaichiro
K
Sasa
Takayoshi
T
Koike
D029662:Betula / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D002245:Carbon Dioxide / Q000494:pharmacology*; D018515:Plant Leaves / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D054046:Plant Stomata / Q000187:drug effects / Q000502:physiology; D029963:Quercus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D012987:Soil; D014867:Water / Q000502:physiology*
D012987:Soil; D014867:Water; D002245:Carbon Dioxide