The Tree Growth and Water Relation of Boreal Forest

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。应变计粘在几棵树内树皮表面的切向上。在整个季节测量切向应变的日变化。冬天在北方森林里，树干里的水结成冰。在此期间，应变的日变化与零度以下气温变化后冰的收缩和膨胀密切相关。这是一年来规模最大的一次运动。2)初春，白桦通过树干上钻的洞渗出汁液。汁液渗出持续了一个月，直到花和叶开放时才停止。该菌株的日变化量在年内最低。在这段时间里，树木似乎一直保持着正压力，把汁液送到花蕾和树叶上，让它们生长和开放。在春夏两季落叶后，大树又长出来了。这一时期菌株的日变化与冬季的变化成反比。即太阳升起后气温开始上升时，桶开始收缩，持续收缩至中午，傍晚气温开始下降时，桶开始收缩。到了晚上，收缩的地方又恢复了，比前一天开始的时候肿胀了一些。这种变化似乎与叶片蒸腾和根系吸水之间的平衡有关。由于蒸腾和光合作用活性较高，晴天变化较大，阴雨天变化较小，蒸腾和光合作用活性较低。4)画出树干的生长曲线，将收缩与释放之间的差异与随后的膨胀进行积分。生长速率在7月底达到最大值，并逐渐向落叶方向下降。少

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