ISA Certified Arborist Practice Exam

The term "winter burn" refers specifically to leaf damage that occurs due to cold, dry winds combined with exposure to sunlight during winter months. This condition typically affects broadleaf evergreens and can manifest as browning or crisping of leaf margins. During the winter, when the ground is frozen, trees may struggle to take up sufficient water due to reduced root activity. Meanwhile, strong winds can lead to increased transpiration, causing the leaves to lose moisture rapidly. If this loss exceeds the water uptake of the roots, the leaves can become desiccated, leading to the symptoms associated with winter burn.

Understanding this condition is crucial for proper tree care during the winter months, as it emphasizes the importance of protecting trees from harsh environmental conditions that can lead to stress and subsequent damage. Careful placement of evergreen trees and, when necessary, protective measures like windbreaks can mitigate the risks associated with winter burn.