ISA Certified Arborist Practice Exam 2025 – All-in-One Resource for Comprehensive Exam Success!

Environmental factors play a crucial role in influencing tree health in various ways, and the option that highlights pollution and drought is particularly significant. Trees, like all living organisms, are affected by their surroundings, and conditions such as air quality and water availability can have profound impacts on their vitality.

Pollution can introduce harmful substances into the environment, affecting both the soil quality and the atmosphere around trees. For instance, pollutants can hinder photosynthesis and damage leaf tissues, reducing a tree's ability to grow and produce energy. Drought, on the other hand, leads to water stress, which can inhibit a tree’s physiological processes. Insufficient water can compromise the tree's ability to transport nutrients and perform essential functions, leading to a decline in health and increased susceptibility to disease and pests.

Overall, recognizing how multiple environmental factors—including but not limited to pollution and drought—interplay to affect tree health is critical for effective arboriculture practices. The insight that these factors can induce stress in trees underscores the importance of monitoring and mitigating adverse conditions to promote tree longevity and health.