Video and Data for 'Branch orientation: A potential indicator of stem rehydration and water stress'

Stem rehydration and water stress are critical ecohydrological processes in temperate and boreal forests, shaping seasonal water balance and productivity. In snow‑dominated systems, the timing of rehydration signals the transition from winter dormancy to spring growth, yet low‑cost field indicators remain scarce. This dataset documents synchronous stem radius changes and branch posture dynamics in balsam fir (Abies balsamea) during early and late spring (March–May 2022) in the Harp‑4 catchment, Muskoka River Watershed, Ontario, Canada (45°22′N, 79°6′W). High‑frequency dendrometer data were combined with time‑lapse imagery to capture freeze–thaw cycles, snowmelt recharge, and rainfall events, with supporting meteorological data from the Dorset Environmental Science Centre. The repository includes the final compiled video (integrating imagery, dendrometer, and environmental data), processed dendrometer time series, and the code used for visualization. These data provide evidence that branch posture can serve as a qualitative, low‑cost indicator of stem rehydration and subsurface water availability, with further research encouraged across species and forest types. Specifically, this repository contains: README.txt (metadata and processing details) Nehemy_Hackmann_McDonnell_VideoTimelapse_Harp4_Waving_Trees.MP4 (time-lapse video documentation) Harp4_Dendrometer-radius_2022.csv (stem radius time series) RScript-Dendrometer_animation-Nehemy_Hackmann_McDonnell_2025 (.RScript) This dataset was used in the following publication:Nehemy, M. F., Hackmann, C., McDonnell, J.J. Branch position: A potential indicator of stem rehydration and water stress. Hydrological Processes – HPeye. For inquiries regarding data use, please contact Magali Nehemy. This work was conducted on the traditional territory of the Anishinaabeg, including the Ojibway, Chippewa, and Algonquin peoples, whose care for this land continues to guide us. We thank Dr. Barbara (Moktthewenkwe) Wall for sharing her knowledge of the trees and waters, Huaxia Yao (Dorset Environmental Science Centre) for meteorological data, and Jim Buttle for early conversations on Harp‑4. Support was provided by the NSERC Discovery Grant Program (MFN, JJM) and the Dorothea Schlözer Program, University of Göttingen (CAH).树干复水（stem rehydration）与水分胁迫是温带与寒温带针叶林中关键的生态水文过程，调控着区域季节水分平衡与森林生产力。在积雪主导的生态系统中，复水节点标志着植物从冬季休眠向春季生长的转换，但目前仍缺乏低成本的野外监测指标。 本数据集记录了2022年3月至5月，加拿大安大略省马斯卡吉河流域Harp-4集水区内胶冷杉（Abies balsamea）的同步茎半径变化与枝条姿态动态。研究通过高频树干测径仪（dendrometer）数据与延时摄影图像结合，捕捉冻融循环、融雪补给与降雨事件，并辅以多塞特环境科学中心（Dorset Environmental Science Centre）提供的配套气象数据。 本数据集仓库包含最终合成的整合视频（集成图像、树干测径仪与环境数据）、处理后的树干测径仪时间序列数据集，以及用于可视化的代码脚本。本数据集证实，枝条姿态可作为树干复水与地下水分供给状况的定性、低成本监测指标，后续可在更多物种与森林类型中开展相关研究。 具体而言，本数据集仓库包含以下内容： README.txt（元数据与处理细节说明） Nehemy_Hackmann_McDonnell_VideoTimelapse_Harp4_Waving_Trees.MP4（延时摄影视频文档） Harp4_Dendrometer-radius_2022.csv（茎半径时间序列数据） RScript-Dendrometer_animation-Nehemy_Hackmann_McDonnell_2025（R语言脚本文件） 本数据集已应用于以下发表论文：Nehemy, M. F., Hackmann, C., McDonnell, J.J. 《枝条位置：树干复水与水分胁迫的潜在监测指标》，《水文过程（Hydrological Processes）》——HPeye专栏。 若需咨询数据使用相关事宜，请联系Magali Nehemy。 本研究开展于阿尼什纳比族（Anishinaabeg，包括奥吉布瓦、奇珀瓦与阿尔贡金族群）的传统领地，该族群对这片土地的管护至今仍指引着我们的工作。在此感谢Barbara（Moktthewenkwe）Wall博士分享其关于林木与水文的本土知识，感谢多塞特环境科学中心的Huaxia Yao提供气象数据，以及Jim Buttle就Harp-4集水区开展的早期探讨。本研究得到了加拿大自然科学与工程研究委员会发现资助计划（NSERC Discovery Grant Program，MFN、JJM）以及哥廷根大学多萝西娅·施勒泽项目（Dorothea Schlözer Program, University of Göttingen，CAH）的资助。