UPSC | Prelims GS | 2026

With reference to the Living Planet Index (LPI), which one of the following statements is correct?

  1. It directly measures the number of species that have become extinct.
  2. It is based exclusively on plant populations and invertebrates.
  3. It tracks changes in populations of monitored vertebrate species using rates of change aggregated through a geometric mean.
  4. A decline in the index proves that the same percentage of all species has declined.

Answer

Correct Answer

It tracks changes in populations of monitored vertebrate species using rates of change aggregated through a geometric mean.

Explanation

Interpreting the LPI

  • Option C is correct: the index aggregates trends in monitored mammal, bird, reptile, amphibian and fish populations.
  • Option A is wrong because the LPI does not count extinctions directly.
  • Option B is wrong because plants and invertebrates are not its principal dataset.
  • Option D is wrong because an index trend is not the percentage of all species declining.

Topics: biodiversity assessment, environment and ecology, living planet index, vertebrate population trends and geometric mean