Water potential gradient between sapwood and heartwood as a driving force in water accumulation in wetwood in conifers
Water potential gradient between sapwood and heartwood as a driving force in water accumulation in wetwood in conifers
复制标题
边材和心材之间的水势梯度作为针叶树湿材积水的驱动力
DOI：
10.1007/s00226-019-01081-4
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发表时间：
2019
影响因子：
3.4
通讯作者：
Nagai Satoshi
中科院分区：
文献类型：
--
作者：
Nakada Ryogo;Okada Naoki;Nakai Takahisa;Kuroda Katsushi;Nagai Satoshi
湿材是指树木树干心材中的水分积累，是林木的一种缺陷，需要进行改良以利于木材的利用。为了了解湿材形成的机理，研究了心材和边材的水势差异及其季节变化。用干湿球法测定了两种针叶树种树干上取样的水势，每隔4周测定一次，历时2年。从边材到心材的水势梯度可以提供径向水分运动的驱动力，并且发现该梯度具有季节性波动。这两种植物的水势季节变化不同。水势梯度的来源被认为是心材中积累的钾和心材中的水溶性物质。提出的假设，从边材心材湿材形成过程中的水运动涉及蒸汽，而不是液体水，并发生在一个有限的季节。
Wetwood, water accumulation in the heartwood of tree trunks, is a defect of forest trees and needs to be improved for wood utilization. To understand the mechanism of wetwood formation, differences in water potential between sapwood and heartwood and their seasonal changes were investigated. The water potential of specimens sampled from tree trunks using an increment corer was measured by psychrometry at four-week intervals for 2 years in two coniferous species. A water potential gradient from sapwood to heartwood was identified that could provide a driving force of the radial water movement, and this gradient was found to fluctuate seasonally. The two species studied differed in seasonal change in water potential. The source of the water potential gradient is thought to be heartwood-accumulated potassium and water-soluble heartwood substance. The hypothesis is proposed that water movement from sapwood to heartwood during wetwood formation involves vaporous rather than liquid water and occurs over a limited season.