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Water movement and characteristics of dry resistance of tree species in a system of soil-trees

土壤-树木系统中树种的水分运动及抗旱特性

基本信息

批准号：
03454072
负责人：
AIBA Yoshinori
金额：
$ 3.84万
依托单位：
Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

(1) The seasonal variatios of the nocturnal concentrations of the major inorganic ions in the branch xylem sap of 11-year-old Mizuki was studied by vacuum extraction using an attached branch. There were increase in the concentrations of most ions just prior to leaf emergency followed by rapid decreases as the leaves expanded. On a clear summer day, the inorganic ion concentrations of branch xylem sap were maximum at noon and minimum at hight. The time and duration of sampling need to be considered when sampling branch xylem sap in investigating nutrient concentration.(2) Daily and seasonal changes of the xylem pressure potential (XPP) of foliage were measured to clarify the characteristics of water stress of some major trees (Iatsura, Metasequoia, Keyaki, Shirakashi) in an urban park. XPP values of the lower part of the crown were the same regardless of weather it was sunny or cloudy weather. XPP of Shirakashi during the night was obviously high in year of large amounts of precipitation. During the daytime. XPP of Shirakashi and Keyaki increased with precipitation during the summer. The transpiration resistance of Keyaki and Shirakashi seemed to be higher than that of Katsura and Metasequoia.(3) The effects of previously reduced soil water content on the recovery of XPP were investigated using ptted seedling of Keyaki and Mizunara. Seedlng resistance to water stress after the soil drying treatment seemed to increase with the severity of the treatment even through it was of sort duration.

(1)采用附枝真空提取法研究了11年生水木枝木质部汁液中主要无机离子夜间浓度的季节变化。大多数离子浓度在叶片膨大前呈上升趋势，随后随着叶片膨大迅速下降。在晴朗的夏季，树枝木质部汁液中无机离子浓度在中午最高，在晚上最低。在对枝条木质部汁液进行养分浓度调查时，需要考虑采样的时间和持续时间。(2)测定了城市公园内主要乔木（水杉、水杉、木树、白石）叶片木质部压力势（XPP）的日变化和季节变化，阐明了水分胁迫的特征。无论晴天还是阴天，树冠下部的XPP值都是相同的。白石县夜间XPP值在降水量大的年份明显偏高。在白天。白石县和木崎县的XPP随着夏季降水的增加而增加。木木和白木的抗蒸腾能力似乎高于桂树和水杉。(3)利用木崎和水原的盆栽苗，研究了土壤含水量降低对XPP恢复的影响。土壤干燥处理后的种子对水分胁迫的抗性随着处理的严重程度而增加，即使是在相同的持续时间内。