The Bangladesh Sundarbans is the largest continuous mangrove in the world that providing crucial environmental services, particularly related to coastal protection and livelihoods of millions of people. However, anthropogenic disturbances, diseases infestation and environmental changes including sea level rise (SLR) and fresh-water flux into the delta are threatening the Sundarbans and other mangrove ecosystems worldwide. Protection of mangrove ecosystems requires knowledge on factors that mainly drive growth and vitality of tree species to evaluate which consequences can be expected from, mainly hydrology-related, environmental changes. In this study, we assessed the nature and periodicity of tree rings in Excoecaria agallocha, a wide spread mangrove species in the Bangladesh Sundarbans. We also analysed the influence of climatic factors, such as precipitation, temperature and vapor pressure deficit (VPD), and river discharge, as a proxy of salinity on ring width (RW) and vessel features, such as mean vessel area (MVA) and mean vessel density (MVD). E. agallocha forms distinct tree-ring boundary that characterized by a narrow (2–4 cells wide) band of radially flattened fibres. The RW as well as the MVA and MVD are crossdatable. The RW is mainly driven by salinity which is influenced by freshwater inputs through precipitation during monsoon along with river discharge January to April. The MVA and MVD responded to similar seasons and months as RW, but mostly with opposite signs in MVD. The results suggest that fresh water inputs through precipitation and river discharge positively influence the radial growth of E. agallocha in the Sundarbans. The RW and vessel features can be used as proxies to explore the growth dynamics of this species, especially in relation to global environmental changes.

孟加拉孙德尔本斯是世界上最大的连续红树林，提供重要的环境服务，特别是与海岸保护和数百万人的生计有关。然而，人为干扰、疾病侵袭和环境变化，包括海平面上升 (SLR) 和流入三角洲的淡水，正在威胁全球的孙德尔本斯和其他红树林生态系统。保护红树林生态系统需要了解主要驱动树种生长和活力的因素，以评估主要与水文相关的环境变化会产生哪些后果。在这项研究中，我们评估了Excoecaria agallocha树木年轮的性质和周期性，一种广泛分布于孟加拉孙德尔本斯的红树林物种。我们还分析了气候因素的影响，如降水、温度和蒸汽压差 (VPD) 以及河流流量，作为盐度对环宽 (RW) 和船只特征的代表，如平均船只面积 (MVA) 和平均血管密度 (MVD)。乙。阿加洛查形成独特的树轮边界，其特征是径向扁平纤维的狭窄（2-4 个细胞宽）带。RW 以及 MVA 和 MVD 是可交叉日期的。RW 主要由盐度驱动，盐度受淡水输入影响，通过季风期间的降水以及 1 月至 4 月的河流流量。MVA 和 MVD 对与 RW 相似的季节和月份做出反应，但在 MVD 中大多具有相反的迹象。结果表明，通过降水和河流排放的淡水输入对E的径向生长有积极影响。孙德尔本斯的agallocha。RW 和船只特征可用作代理来探索该物种的生长动态，尤其是与全球环境变化相关的情况。