The effects of the water stress in summer dry period on sap water movement in cross-sectional xylem of a trunk of Liquidamber formosana Hance (An11-year-old tree) were investigated by the heat pulse method for four months. Under the suitable water conditions with frequent rainfalls, diurnal changes in sap-flow rates at every part of the cross-sectional xylem within 13 mm of the surface of a trunk were very similar to each other and mainly were correlated with the saturation deficit of the air. On the other hand, under the dry conditions in summer drought period, these rates were suppressed in different manners in each part of a tree trunk and the patterns of the diurnal changes of them became different from each other. Even after a long dry period, the sap flow rates in the main conducting parts of xylem could recover immediately after a rainfall. However, the recovery of the ascent of sap water in outer part of xylem was taken for more than two weeks after a rainfall, indicating the difference in the responses of the sap water movement in each-cross-sectional part of the tree trunk to the changes in the condition of water supply.
|Number of pages||1|
|Journal||Nihon Ringakkai Shi/Journal of the Japanese Forestry Society|
|Publication status||Published - 1994|
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