The correct matching between List I and List II is as follows:
| List I | List II |
|---|
| Robert May | Global species diversity at about 7 million |
| Alexander von Humboldt | Species-Area relationship |
| Paul Ehrlich | Rivet popper hypothesis |
| David Tilman | Long term ecosystem experiment using outdoor plots |
Explanation:
- Robert May is known for his work on estimating global species diversity, which is around 7 million.
- Alexander von Humboldt introduced the concept of the species-area relationship.
- Paul Ehrlich proposed the "Rivet Popper Hypothesis," suggesting the ecological importance of species.
- David Tilman conducted long-term ecosystem experiments using outdoor plots to study biodiversity and ecosystem function.
Thus, the correct pairing is: A-III, B-I, C-IV, D-II.