摘要
使用压力室和Pressure-Volume曲线方法研究栓皮栎Quercus variabilis Bl。苗木根系和枝叶的水势及其几个主要水分参数的变化。土壤水分良好时,枝叶水势的日变化最低可达-2.0MPa,根系可达-0.8MPa,气孔开始关闭时木质部水势为-2.0～-2.6MPa。根系的水分释放曲线有明显的季节变化,秋季曲线的斜率最小;共质体水含量为18.84％～52.42％,弹性模量值最大为8.6MPa,最小为6.5MPa。枝叶中水分释的曲线也有季节变化,整个生长季中共质体水含量为38.51％～81.95％,具有与根系相似的变化趋势;弹性模量值最大为15.7MPa,最小为9.2MPa。结合苗木的生长发育进程及环境因子的变化分析了水分参数变化的原因。
Changes of water potential and selected water parameters were studied in the shoot and root systems of oriental oak seedlings using a pressure chamber and the pressure-volume curve method.When well watered,diurnal changes of xylem water potential reached a minimum of -2.0MPa and -0.8MPa in roots,xylem water potential while leaf stomota start to close at about -2.0^-2.6MPa.In root systems,the water release curve changes seasonally.Its slope is minimal in autumn and the range of symplast water content is 18.84%~52.42%,while tissue elastic modulus varies between 6.5MPa and 8.6MPa.In shoots,the range of symplast water content is 38.51%~81.95%.Similar trends occur in roots where tissue elastic modulus changes from 9.2MPa to 15.7MPa.The change is lowest in early summer and highest in late autumn.The reasons for water parameter changes are discussed in relation to the phenological developmental stages and environmental factors.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
1990年第3期26-33,共8页
Journal of Beijing Forestry University
关键词
栓皮栎
苗木
水分关系
oriental oak,water parameter,seasonal changes
