1993 Fiscal Year Final Research Report Summary
Water movement and characteristics of dry resistance of tree species in a system of soil-trees
| Project/Area Number |
03454072
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
林学
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
AIBA Yoshinori The United Graduate School of Agriculture Science, Professor, 連合農学研究科, 教授 (00014944)
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| Co-Investigator(Kenkyū-buntansha) |
HAIBARA Kikuo Fculty of Agreculture, Processor, 農学部, 教授 (00014960)
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| Project Period (FY) |
1991 – 1993
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| Keywords | dry resistance / water stress / xylem pressure potential / transpiration / xylem sap / pressure chamber / semiarid silviculture / vacuume extraction |
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| Research Abstract |
(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.
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