Which type of ecosystem service supports the functioning of all other ecosystem services?

• A. Cultural services
• B. Provisioning services
• C. Supporting services
• D. Regulating services

Answer: (C)

The key idea is that some ecosystem services provide the foundation that enables all the other services to function. Supporting services encompass the ecological processes and features that keep ecosystems healthy and functioning—things like soil formation, nutrient cycling, biodiversity maintenance, and primary production. These processes create the conditions under which provisioning (like food and water), regulating (such as climate and flood control), and cultural (recreation and aesthetics) services can occur and be sustained over time. If these underlying processes weaken, the capacity of all the other service types to deliver their benefits also declines, which is why this category is the best answer. The other service types describe benefits or outputs themselves rather than the foundational processes that support everything else.