Hydraulic architecture and internal water storage of Japanese cypress using measurements of sap flow and water potential
Hydraulic architecture and internal water storage of Japanese cypress using measurements of sap flow and water potential
复制标题
利用液流和水势测量研究日本柏树的水力结构和内部蓄水
DOI：
10.1002/eco.2325
复制
发表时间：
2021
期刊：
影响因子：
2.6
通讯作者：
Kosugi Yoshiko
中科院分区：
文献类型：
--
作者：
Kamakura Mai;Tsuruta Kenji;Azuma Wakan A.;Kosugi Yoshiko
通过对一棵60年生日本扁柏（Chamaaparis obtusa）的液流速率（u）和土壤、树干、树枝和树叶沿着水力系统的原位水势（μ）的同步测量，研究了其水力结构和内部储水量。在整个生长季中，侧枝和叶片等远端器官的导水率均低于茎，茎上部与侧枝之间的导水率（K）最低。与上部茎的水流相比，潜热通量（IE）在早上提前约1小时开始增加，在晚上提前0.5-1小时停止，与太阳辐射和水汽压赤字的变化相一致。我们还观察到一个明显的时间滞后（约2小时）inuand茎的基部和上部之间的早晨和晚上的休息。尽管茎基部和上部的E、u和K在中午前后都达到峰值，但这两个参数的日变化曲线不同。这些差异表明，储存在茎和叶的水是在早上撤出，从土壤中吸收水分之前，而在晚上的差异点，它的补充。虽然干储水的贡献是约5%的日蒸腾，这是可能的水力结构的C。obtusaminates维持水分运输效率的最外层的冠层，高蒸腾需求。
We studied the hydraulic architecture and internal water storage of a 60‐year‐old Japanese cypress tree (Chamaecyparis obtusa) by concurrent measurements of sap flow rates (u) and in situ water potential (Ψ) of the soil, stem, branches and leaves along the hydraulic system over a year. Distal organs such as lateral branches and leaves showed lowerΨthan that of stem throughout the year, and the lowest hydraulic conductance (K) was shown between the upper stem and lateral branches. Compared to water flow in the upper stem, latent heat flux (lE) began increasing at approximately 1 h earlier in the morning and ceased at 0.5–1 h earlier in the evening, coinciding with variations in solar radiation and vapour pressure deficits. We also observed a distinct time lag (~2 h) inuandΨbetween the basal and upper portions of the stem in the morning and evening. AlthoughlE,uandΨpeaked near noon in both the basal and upper portions of the stem, the two parameters exhibited different diurnal curves. These differences suggest that water stored in the stem and foliage is withdrawn in the morning, prior to water uptake from the soil, whereas differences in the evening point to recharge of it. Although the contribution of stem water storage was approximately 5% of daily transpiration, it is possible that hydraulic architecture ofC. obtusamaintains the water transport efficiency on the outermost layer of the canopy where high transpiration demand.
影响因子：
2.3
作者：
HERZOG, KM;HASLER, R;THUM, R
通讯作者：
THUM, R