With the development of water detection instruments, it is feasible to detect the stem liquid water content. However, real-time and non-destructive monitoring of liquid water and ice content of plant stems in winter remains challenging. Here, we developed a living wood freeze–thaw detection (LWFTD) sensor to detect the liquid water and ice content of plant stems in situ, in real time, and micro-destructively. First, based on the latent heat effect and using a retractable ring-type shrapnel probe, we monitored the freeze–thaw front of the stem water in real time and micro-destructively. Second, using calibration data and infrared detection data, the reliability of the LWFTD sensor and the feasibility of stem freeze–thaw detection based on the latent heat effect were proven. Finally, by simulating a freeze–thaw cycle and analyzing the changes in the stem liquid water content and stem temperature, an ice content model was constructed to calculate the ice content and freeze–thaw fronts. In field experiments, we recorded stem water content and freeze–thaw data of Pachira glabra, Populus tomentosa, and Lagerstroemia indica during an overwintering period. The results showed that the LWFTD sensor can effectively detect the changes in water-related physiological parameters during plant freeze–thawing in real time and that the ice content in the stem volume exhibits diurnal changes, with a single-peak, single-valley wave pattern. Our study provides a reference for evaluating the effects of freeze–thaw on plant metabolism and vitality. Furthermore, this study provides an advanced technical tool for in situ, real-time, and micro-destructive monitoring of the water and ice content in plant stems, which will help further our understanding of the water transport process and freeze–thaw-induced embolism of woody plants during winter.

随着水分检测仪器的发展，检测茎秆液态含水量已成为可能。然而，在冬季对植物茎的液态水和冰含量进行实时和无损监测仍然具有挑战性。在这里，我们开发了一种活木冻融检测 (LWFTD) 传感器来原位检测植物茎的液态水和冰含量，实时，微破坏性。首先，基于潜热效应并使用可伸缩的环形弹片探头，我们实时、微破坏地监测了茎水的冻融前沿。其次，利用标定数据和红外检测数据，证明了LWFTD传感器的可靠性和基于潜热效应的茎干冻融检测的可行性。最后，通过模拟冻融循环，分析茎秆液态水含量和茎秆温度的变化，构建了冰含量模型来计算冰含量和冻融前沿。在田间试验中，我们记录了光子红、毛白杨和紫薇的茎含水量和冻融数据在越冬期间。结果表明，LWFTD传感器可以有效实时检测植物冻融过程中与水分相关的生理参数变化，茎体积中的冰含量呈昼夜变化，呈单峰单谷波型。 . 本研究为评价冻融对植物代谢和活力的影响提供了参考。此外，这项研究为对植物茎中的水和冰含量进行原位、实时和微破坏性监测提供了一种先进的技术工具，这将有助于我们进一步了解水分输送过程和冻融诱发的栓塞。冬季的木本植物。