ISA Certified Arborist Practice Exam

What role do trees play in nutrient cycling within an ecosystem?

1. They act as sediment traps

2. They produce and decay organic matter

3. They filter pollutants

4. They primarily grow in nutrient-poor areas

The correct answer is: They produce and decay organic matter

Trees play a critical role in nutrient cycling within an ecosystem primarily by producing and decaying organic matter. Through the process of photosynthesis, trees convert sunlight into energy, creating biomass in the form of leaves, roots, and wood. When leaves fall and decompose, or when trees die, they contribute organic matter back into the soil. This organic matter is rich in nutrients, which are essential for the growth of other plants and organisms within the ecosystem. The decomposition process also enhances soil structure and promotes the activity of soil microorganisms, further aiding in the cycling of nutrients. Understanding the role of trees in producing and decaying organic matter helps clarify their importance in maintaining healthy ecosystems, as this process is fundamental to sustaining plant growth and supporting food webs.