Vegetation canopy structure and function determine global rates of photosynthesis and transpiration and, thus, heavily influence the global carbon, water, and energy cycles. Key unknowns remain regarding how plant canopies respond to both temporal and spatial mesoclimatic changes, and the within-canopy microclimate. In this session, we will explore the relative roles of leaf physiology and traits, and canopy phenology, microclimate, and structure, in determining ecosystem states and rates. We are particularly interested in studies that use novel approaches to examine changes in canopy form and function, particularly those that bridge traditional boundaries with new theory, observations, and models. We encourage submissions focused on vegetation canopies at any scale, including near-surface or remote sensing techniques, field and experimental observations. We also encourage empirical and modeling submissions examining canopy processes across scales, from seconds to decades and from the leaf to the globe.