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。大部分通过微小导管输送的水分从叶片中蒸发，这称为蒸腾作用。植物中的蒸腾速率受叶表面附近的两种结构的极大影响：气孔（即，叶片表面上的小开口）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显微结构所包围，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环境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交和沟通能力受损的人提供农业培训和个性化工作。本项目的目标是通过物理控制实验和理论分析，了解非生物对植物蒸腾速率的影响。物理实验将控制植物周围的空气流动，这在改变相对湿度和边界层方面起着至关重要的作用。当空气围绕柔性叶片流动时，边界层的形状和大小在植物周围不是静止的，而是在空间和时间上动态的。描述这种边界层的动态变化将使我们更好地了解不同条件下的蒸腾速率。此外，叶表面上的微结构影响植物周围的蒸汽浓度，因为液滴冷凝或蒸发。总的来说，这种变化的气孔附近的蒸汽流量和可变边界层将影响植物的生理性能。因此，蒸腾速率和外部流体和表面特性之间的相互作用应被表征，以阐明自然植物与环境的相互作用。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.