The Tree Growth and Water Relation of Boreal Forest

北方森林的树木生长与水分关系

• 批准号: 08456083
• 负责人: TERAZAWA Minoru
• 金额: $ 4.8万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08456083/
• 关键词: Water Relation; Tangential Strain; Sap Exudation; Root Pressure; Water Absorption; Transpiration; Freezing Tolerance; Tree Growth; 吸水; 樹液

The Tree Growth and Water Relation in Boreal ForestThe tree growth and water relation in boreal forests were investigated. Strain gages were glued in the tangential direction of the surface of the inner bark of several trees. Diurnal change in the tangential strain were measured throughout the seasons.1) In winter in the boreal forests, the water in the tranks of trees frozen into ice. The diurnal change of the strain during this period coinsided with the shrinkage and swelling of the ice following the change of air temperature under zero degrees centigrate. The movement was the largest in a yaer.2) In early spring, shirakamba birch exudated sap through a hole drilled on the trank. Sap exudation continued for one month and stopped just on time when flowers and leaves opened. The diurnal change of the strain was the lowest in the year. Trees seemed to keep a positive pressure throughout this period for sending the sap up to the buds of flowers and leaves for their growth and opening.3) … More In spring and summer after the leaf opening, tree growed. The diurnal change of the strain in this period varied inversely with the change observed in the winter season. Namely, the trank started to shrink when air temperature started to rise after sun rise and shrinked continuously till noon and released the shrinkage when air temperature started to fall down toward evening. During night the shrinkage was revovered and swelled a little more than the starting point of the day before. The change seemed to coinside with the balance of the activities between transpiration of the leaves and water absorption from the roots. The changes were higher in sunny days because of higher transpiration and photosynthesis activities and were lower in rainy days with their lower activities.4) The growth curve of the trank was drawn as an integration of the difference between the shrinkage and the release of the shrinkage and following swelling. A maximum of the growth rate was observed on the end of July and the rate decreased gradually toward defoliation. Less

北方森林树木生长与水分关系研究了北方森林树木生长与水分关系。应变片粘在几棵树的内树皮表面的切线方向。1）冬季，北方森林树木树干中的水分冻结成冰。在此期间，应变的日变化与零度以下气温变化引起的冰的收缩和膨胀相一致。早春，白桦树通过在树干上钻的一个洞渗出树液。汁液分泌持续了一个月，并及时停止时，花和叶开放。该菌株的日变化是全年最低的。在这段时间里，树木似乎一直保持着一种正压力，将树液输送到花蕾和叶子上，使它们生长和开放。 ...更多信息 在春季和夏季叶片开放后，树生长。在此期间，应变的日变化与冬季观察到的变化相反。也就是说，当太阳升起后气温开始上升时，树干开始收缩，并持续收缩到中午，当气温接近傍晚时开始下降时，收缩解除。到了晚上，收缩被逆转，比前一天的起点膨胀了一点。这种变化似乎与叶片蒸腾和根系吸水之间的活动平衡一致。结果表明，在晴天，蒸腾和光合活性较高，变化幅度较大;在雨天，蒸腾和光合活性较低，变化幅度较小。生长速率在7月底达到最大值，随着落叶量的增加，生长速率逐渐下降。少