ISA Certified Arborist Practice Exam

Mycorrhizal fungi play a crucial role in tree health by enhancing nutrient absorption and improving soil structure. These fungi form symbiotic relationships with the roots of trees and other plants, significantly expanding the root system's surface area. This extended network allows trees to access water and essential nutrients such as phosphorus and nitrogen more effectively than they could with their roots alone.

Additionally, mycorrhizal fungi contribute to soil structure by creating a stable network of hyphae, which helps bind soil particles together. This improved soil structure enhances water retention and aeration, both of which are vital for healthy root development and overall tree vitality. Thus, the symbiosis fosters a healthier ecosystem for trees, leading to better growth and resilience against environmental stressors.

While mycorrhizal fungi can have indirect effects on other aspects of tree health, such as potentially influencing growth hormone levels or impacting plant interactions with pests, their primary role is firmly centered on enhancing nutrient absorption and improving soil conditions.