Leaf Angle of North America Broadleaf Deciduous Trees: 2021 - 2023

Leaf angle, defined as the angle between the leaf normal (perpendicular to the leaf surface) and the zenith, strongly influences albedo, photosynthesis, and evapotranspiration. We installed remote time-lapse cameras mounted level with the sunlit treetops at each of the ten National Ecological Observatory Network (NEON) tower to measure and track seasonal changes of leaf angle for 11 tree species across three years of 2021, 2022 and 2023. We measured the (x, y) coordinates of each leaf’s petiole and tip and tracked their changes over time on a weekly basis. From these coordinates, we computed the leaf angle for each leaf throughout the growing season across three years of weekly observations.