Certified Arborist Practice Exam

Do most soil organisms cause disease or decay in tree roots?

1. True

2. False

The correct answer is: False

Most soil organisms do not cause disease or decay in tree roots; in fact, many are beneficial to plant health. Beneficial soil organisms, such as certain bacteria and fungi, play a vital role in nutrient cycling, breaking down organic matter, and forming symbiotic relationships with tree roots. For example, mycorrhizal fungi enhance nutrient uptake in trees by extending their root systems through the soil, facilitating access to water and essential nutrients. While some soil organisms can be pathogenic and lead to diseases or decay, the majority contribute to the establishment of healthy roots and overall tree vitality. This balanced ecosystem in the soil is essential for promoting tree growth, resilience, and recovery from stress. It's important to recognize the diverse roles soil organisms play in the ecosystem, as most are critical for the health of tree roots and the surrounding soil environment.