Which statement describes disturbances that test an ecosystem's resilience?

• A. Disturbances such as wildfires or floods can test resilience by rearranging species composition.
• B. Ecosystems are never disturbed.
• C. Disturbances always increase biodiversity.
• D. Disturbances never affect energy flow.

Answer: (B)

The main idea here is how ecosystems respond to disturbance and what that reveals about resilience. Resilience is about an ecosystem’s ability to absorb a disturbance, maintain its essential functions (like energy flow and nutrient cycling), and either return to its former state or reorganize into a stable new one. Disturbances such as wildfires or floods challenge the system and often change which species are present and how they interact. Because some species survive, others recolonize, and competitive relationships shift, the community composition can rearrange. This rearrangement tests whether the ecosystem can recover its functions and structure after the disruption.

That’s why describing resilience in terms of disturbance rearranging species composition is the best fit. The statements that ecosystems are never disturbed, that disturbances always increase biodiversity, or that disturbances never affect energy flow don’t align with how real ecosystems respond: disturbances do occur, can reduce or alter biodiversity, and can change energy flow and ecosystem processes.