Tree rings from ring-porous species have often been used as flood proxy. Many ring-porous species produce characteristic flood rings in response to stem submersion during vessel formation. Flood rings have earlywood vessels that are more numerous and/or of smaller cross-sectional area than “normal” rings. This study aimed at determining if diffuse-porous balsam poplar and trembling aspen, like ring-porous black ash, produce anatomically distinct annual tree rings in response to flooding. More specifically, we asked (i) if periodic tangential bands of vessels (hereafter PTBV) could be as easily identified/quantified as flood rings and (ii) if PTBV could be associated with spring flooding. Sampling of black ash, balsam poplar and trembling aspen trees took place along a flood exposure gradient in the floodplain of Lake Duparquet in northwestern Québec. Two observers recorded flood rings and PTBV. Consistency between observers was greatest when identifying flood rings. In both diffuse-porous species, PTBV occurred less abundantly than flood rings in black ash. They also occurred less often in balsam poplar than in trembling aspen. Years in which PTBV were initiated early in the growing season were associated with years in which flood rings occurred. Like flood rings, early occurring PTBV were more abundant in springs characterized by high mean river discharge, extensive snow cover, cold temperatures and heavy precipitation. Early-occurring PTBV dominated in flooded sites and late-occurring ones dominated in the control site. However, PTBV of the late-types were also observed in both flood exposures indicating that spring flood may not be the only factor modulating their formation. While flood rings seem to be associated with a change in the transport of growth regulators resulting from stem submergence and excess water, PTBV may be reflective of rhythmic alterations in the transport of growth regulators resulting from either water excess or deficit. Despite promising findings, many questions remain before PTBV in riparian diffuse-porous species can be widely used as a flood proxy. Why do species and individual trees differ in their ability to record them? What is the full range of environmental conditions triggering PTBV’s formation especially in unflooded sites and in the late growing season?

环孔树种的年轮经常被用作洪水代理。许多环孔物种会在血管形成过程中响应茎的浸没而产生特征性的洪水环。洪水环具有比“正常”环多的早材容器和/或较小的横截面积。这项研究旨在确定散孔香脂杨树和颤杨树，如环孔黑灰树，是否会产生解剖学上不同的年轮以响应洪水。更具体地说，我们询问（i）是否可以像洪水环一样容易地识别/量化周期性的船只切向带（以下简称 PTBV），以及（ii）PTBV 是否与春季洪水有关。黑灰取样，在魁北克西北部 Duparquet 湖的洪泛区，沿着洪水暴露梯度发生了香脂杨树和颤抖的白杨树。两名观察员记录了洪水环和 PTBV。在识别洪水环时，观察者之间的一致性是最大的。在这两种漫孔物种中，PTBV 的发生量低于黑灰中的泛光环。它们在香脂杨树中的出现频率也低于在颤抖的白杨树中的出现频率。PTBV 在生长季节早期开始的年份与洪水环发生的年份有关。像洪水环一样，早期发生的 PTBV 在具有高平均河流流量、广泛积雪、寒冷温度和强降水的春季中更为丰富。早期发生的PTBV在淹没地点占优势，而晚期发生的则在控制地点占优势。然而，在两次洪水暴露中也观察到晚型的 PTBV，表明春季洪水可能不是调节其形成的唯一因素。虽然洪水环似乎与茎浸没和水分过多导致生长调节剂运输的变化有关，但 PTBV 可能反映了由于水分过多或不足导致的生长调节剂运输的节律性变化。尽管发现有希望，但在河岸扩散多孔物种的 PTBV 可广泛用作洪水代理之前，仍有许多问题。为什么物种和个别树木的记录能力不同？触发 PTBV 形成的所有环境条件是什么，尤其是在未淹没的地点和生长后期？为什么物种和个别树木的记录能力不同？触发 PTBV 形成的所有环境条件是什么，尤其是在未淹没的地点和生长后期？