摘要
在温室条件下 ,控制不同干旱梯度 ,用改良的冲洗法测定了 4年生油松、侧柏苗木的水力结构参数 .研究表明 ,随着小枝水势的降低 ,水力结构各参数随茎段功能木质部直径的变化可以用不同的方程来模拟 ;油松苗木在轻度水分胁迫下导水率剧烈丧失 ,侧柏苗木在中度水分胁迫下导水率剧烈丧失 .在落叶之前 ,相同直径油松和侧柏苗木枝条的胡伯尔值随小枝水势的变化很小 ,说明苗木水分胁迫主要源于木质部空穴和栓塞 .油松、侧柏苗木在干旱过程中水力结构的不同变化趋势 。
The hydraulic architecture parameters of Pinus tabulaeformis and Platycladus orientalis (4 years old) seedlings were measured by improved flushing method under the condition of controlling drought gradient in the green house. The study indicates the changes of hydraulic architecture parameters with stem segment functional xylem diameter can be modeled by different equation with the decreased twig water potential. The hydraulic conductivity of Pinus tabulaeformis seedlings evidently decreased in light water stress, and that of Platycladus orientalis seedlings did so in medium water stress. The change of Huber value of same diameter Pinus tabulaeformis and Platycladus orientalis seedling branches with twig water potential is little before defoliation. So the main reason of seedling water stress is because of xylem cavitation and embolism. The different variation trends of Pinus tabulaeformis and Platycladus orientalis seedlings in hydraulic architecture characteristics during drought is favor to people's understanding on trees water physiology trait from new point of view.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2002年第5期45-49,共5页
Journal of Beijing Forestry University
基金
国家自然科学基金资助项目 ( 30 0 70 6 37)
教育部高等学校博士点基金及骨干教师资助项目
关键词
干旱胁迫
油松
侧柏
苗木
水力结构特征
冲洗法
水势
Pinus tabulaeformis, Platycladus orientalis, flushing method, hydraulic architecture, water potential
