An organism survives a difficult winter. The populations in an area remain the same. One species replaces another species in an ecosystem. Each of several species uses the same amount of resources.
I gave my students this multiple choice question: Which situation is the best example of ecological succession?

Only one answer is correct among these 4 choices:
- An organism survives a difficult winter.
- The populations in an area remain the same.
- One species replaces another species in an ecosystem.
- Each of several species uses the same amount of resources.

Could you tell me which one is correct?

One species replaces another species in an ecosystem.