Why does biodiversity loss reduce resilience?

• A. Ecosystem disturbances have no effect on resilience.
• B. Fewer species mean fewer species performing similar roles; reduced redundancy reduces resilience.
• C. Biodiversity has no effect on resilience.
• D. Biodiversity increases resilience only in stable environments.

Answer: (B)

Biodiversity provides redundancy in ecosystem functions, which supports resilience. When many species share similar roles—like pollination, decomposition, or nutrient cycling—loss of some species doesn’t collapse those processes because others can step in and maintain functioning. This backup system helps an ecosystem absorb disturbances and recover more quickly. If biodiversity is reduced and fewer species are left, there are fewer backups to compensate for losses; a disturbance can knock out a critical function with little chance of replacement, slowing recovery and making the system more vulnerable to lasting change.

Other statements miss this core idea: disturbances do affect resilience, biodiversity does contribute to resilience, and resilience isn’t limited to stable environments—diversity generally helps a system weather a range of conditions by providing multiple ways to maintain function.