Dr. William K. Smith

Plant adaptation to extreme environments: structure versus physiology

Dr. William K. Smith
Wake Forest University

March 30, 2022

Hosted By Dr. Jim Coleman


Due to a general lack of mobility compared to animals, plants must adapt to their environments via changes in structure across the cell to community levels. These adaptations include changes that influence plant temperature, water, and nutrient relations via impacts on photosynthesis and transpirational water loss. Transpiration and photosynthesis (CO 2 uptake) are regulated by stomatal pores that are found primarily on the bottom leaf surface. Yet, sunlight is most commonly incident on the upper leaf surface. Several leaf structural characteristics act to maximize the overlap of absorbed sunlight and CO 2 inside the leaf. Beyond the leaf level, the arrangement and orientation of leaves at the branch, crown, and canopy levels also enable structural adaptations influencing plant photosynthesis and transpiration. Ultimately, these structural adaptations often lead to greater water use efficiency, the ratio of photosynthesis to transpiration.