For an examination of the progression of cavitation in large-diameter earlywood vessels of a deciduous ring-porous tree, potted saplings of Fraxinus mandshurica var japonica Maxim. were frozen and then thawed. The changes in the amount and distribution of water in the lumina of the current year's earlywood vessels during the course of the freezing and thawing were visualized by cryo-scanning electron microscopy. When samples were frozen, most of the current year's earlywood vessels were filled with water. After the subsequent thawing, the percentage of cavitated current-year earlywood vessels gradually increased with time. All of the current year's earlywood vessels were cavitated within 24 h, and only limited amounts of water remained in the lumina of earlywood vessels. Similar cavitation of earlywood vessels was observed after thawing of frozen, excised stem pieces. In contrast, many vessels of the current year's latewood retained water in the lumina during freezing and thawing. These observations indicate that the cavitation of the current year's earlywood vessels is not produced during freezing but progresses during rewarming after freezing in F. mandshurica var japonica.
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机译：为了检查落叶环状多孔树的大直径早木容器中的空化进程，我们使用水曲柳的盆栽树苗。冷冻然后解冻。通过冷冻扫描电子显微镜观察了当年早材容器在冷冻和解冻过程中水的数量和分布的变化。冷冻样品时，当年的大多数早木容器中都装满了水。在随后的解冻之后，空化的本年度早木容器的百分比随着时间逐渐增加。当年的所有早木器皿均在24小时内空化，而早木器皿内仅存有少量水。冷冻的，切下的茎块解冻后，观察到了类似的早木容器气蚀现象。相反，许多当年的红木容器在冷冻和解冻过程中会将水留在管腔中。这些观察结果表明，当年冷冻的F. mandshurica var japonica不会在冷冻过程中产生本年度早木容器的气穴现象，而是在冷冻后的变温过程中进展。
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