ISA Certified Arborist Practice Exam

Why is tree diversity important in urban settings?

1. It aids in soil compaction

2. It reduces noise pollution

3. It enhances ecosystem resilience

4. It minimizes leaf litter

The correct answer is: It enhances ecosystem resilience

Tree diversity plays a crucial role in enhancing ecosystem resilience, particularly in urban settings. Diverse tree species contribute to a more stable environment by promoting biological interactions and improving the overall health of the urban ecosystem. Different species respond uniquely to pests, diseases, and environmental changes; thus, a diverse tree population can reduce the overall risk of widespread tree loss due to a stressor that may affect a specific species. For instance, if a certain pest targets one type of tree, the presence of various other species can help maintain the ecological functions of the area, such as air quality improvement, temperature regulation, and habitat for wildlife. Furthermore, diverse tree populations can improve soil health, support a wider range of beneficial insects, and contribute to a more balanced carbon cycle, all of which are vital for sustaining urban biodiversity and enhancing the ability of the ecosystem to withstand stresses.