ISA Certified Arborist Practice Exam

How do trees help in soil conservation?

1. They increase soil acidity.

2. They improve the soil’s nutrient content.

3. They reduce erosion by stabilizing the soil with their roots.

4. They absorb excess moisture from the soil.

The correct answer is: They reduce erosion by stabilizing the soil with their roots.

Trees play a vital role in soil conservation primarily through their root systems, which help to stabilize the soil. The roots of trees anchor the soil in place, preventing it from being washed away by rain or blown away by wind, thereby significantly reducing erosion. In addition to anchoring the soil, tree roots create a network that enhances soil structure, promoting the retention of water and nutrients, which further contributes to soil health. While trees can influence soil acidity, improve nutrient content through decomposition of fallen leaves and organic matter, and absorb moisture, the mechanism by which they most directly contribute to soil conservation is through their ability to stabilize the soil. This stabilization is crucial in maintaining the integrity of the ecosystem, preventing landslides, and protecting waterways from sedimentation. Thus, the action of reducing erosion through root stabilization is a key reason why trees are critical for soil conservation.