中文摘要：

根据岩溶生境特点设计表层岩溶水-岩石（灰岩）-土壤水分供应分层模拟柱,对青冈栎（Cyclobalanopsis glauca）进行水分控制试验;运用压力容积（P-V）技术,研究了在水分胁迫下青冈栎的日水势（P）、饱和含水量时的最大渗透势（ψssat）、初始质壁分离时的渗透势（ψstlp）、初始质壁分离时渗透水相对含量（ROWCtlp）、初始质壁分离时相对含水量（RWCtlp）、质外体水的相对含量（AWC）,以及饱和含水量时最大渗透势与初始质壁分离时的渗透势之差（ΔP）的变化。结果表明,在无表层岩溶水-岩石-土壤处理中,随着土壤干旱胁迫程度的增加,ROWCtlp、RWCtlp、ψssat、ψtslp呈明显下降,而AWC值上升;在有表层岩溶水-岩石-土壤处理下,青冈栎受土壤水分胁迫不明显,水分参数变化不显著。表层岩溶缺水时,土壤水分含量是影响青冈栎水分参数变化的主要因素,在一定的干旱胁迫范围内,随着干旱程度的提高,青冈栎耐旱性不断增加。

英文摘要：

By using a water supply device with epikarst water-limestone-soil columniation to simulate karst environment,and adopting press-volume（P-V）technique,a water-controlled experiment was conducted to study the changes of Cyclobalanopsis glauca water parameters including daily water potential（P）,water potential at saturated point（ψsats）,water potential at turgor loss point（ψtlps）,relative osmotic water content at turgor loss point（ROWCtlp）,relative water content at turgor loss point（RWCtlp）,relative content of apoplastic water（AWC）,and the difference between ψsats and ψtlps（ΔP）under drought stress.In treatment no-epikarst water-limestone-soil,the ROWCtlp,RWCtlp,ψsats,and ψtlps decreased and the AWC increased with intensifying soil drought;while in treatment epikarst water-limestone-soil,these water parameters had no significant changes along with soil water variation.Under no-epikarst water condition,the water parameters of C.glauca were predominantly affected by soil water content,and the drought tolerance of C.glauca was enhanced with increasing soil drought in a certain range of drought stress.