MCA: Effects of unsteady wind and surface morphology on the plant transpiration

植物需要在根和芽之间运输水和其他物质。大部分水分通过细小的管道从树叶中蒸发，这被称为蒸腾作用。植物的蒸腾速率很大程度上受叶片表面附近的两个结构的影响：气孔（即叶片表面的小开口）和边界层（即扩散过程占主导地位的薄空气层）。这两种结构相当复杂，通常与其他物理和环境因素相结合。气孔被表皮细胞的各种微观结构所包围，边界层受风的强烈影响。因此，研究小组将研究气孔和边界层如何影响叶片与周围空气之间的气体交换。除了以实验室为基础的研究活动外，这项研究将有助于为社会和沟通能力受损的人提供农业培训和个性化工作。该项目的目标是在物理控制实验和理论分析的基础上了解植物蒸腾速率的非生物效应。物理实验将控制植物周围的空气流动，这对改变相对湿度和边界层起着至关重要的作用。当空气在柔性叶片周围流动时，边界层的形状和大小在植物周围不是固定的，而是在空间和时间上动态的。描述边界层的这种动态变化将有助于更好地了解不同条件下的蒸腾速率。此外，当液滴凝结或蒸发时，叶片表面的微观结构会影响植物周围的蒸汽浓度。总之，气孔附近水汽通量的变化和边界层的变化会影响植物的生理性能。因此，蒸腾速率与外界流体和表面性质之间的相互作用应该被表征，以阐明自然植物与环境的相互作用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Plants need to transport water and other substances between the roots and the shoots. Most of the water transported through tiny conduits evaporates from the leaves, which is called transpiration. The transpiration rate in plants is greatly affected by two structures near the leaf surface: stomata (i.e., small openings on the leaf surface) and a boundary layer (i.e., a thin air layer in which the diffusion process is dominant). These two structures are quite complicated and usually coupled with other physical and environmental factors. The stomata are surrounded by various microscopic structures of epidermal cells, and the boundary layer is strongly affected by wind. Therefore, the team will investigate how the stomata and the boundary layer affect the exchange of gases between leaves and the surrounding ambient air. Besides lab-based research activities, this research will contribute to providing agricultural training and individualized jobs to persons with impaired social and communication skills. The goal of the project is to understand abiotic effects on transpiration rate in plants based on physically controlled experiments and theoretical analysis. Physical experiments will control the air flow around plants, which plays a crucial role in altering the relative humidity and the boundary layer. When the air flows around a flexible leaf, the shape and size of the boundary layer are not stationary around the plant, but rather dynamical in space and time. Characterizing such dynamic changes in the boundary layer will allow greater understanding of the transpiration rate under varying conditions. Additionally, microstructures on the leaf surface affect the vapor concentration around the plant as droplets condense or evaporate. Overall, such a varying vapor flux near the stomata and variable boundary layer would affect the physiological performance of plants. Therefore, the reciprocal effects between the transpiration rate and external fluidic and surface properties should be characterized to illuminate natural plant-environment interactions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.