In conservation biology, how is the biodiversity of an ecosystem most commonly measured?

• A. By measuring the total biomass of primary producers per unit area
• B. By measuring the average body size of organisms in the community
• C. By assessing species richness and species evenness, often summarized using a diversity index (e.g., Shannon index)
• D. By counting only the number of keystone species present

Answer: (C)

Verified step by step guidance

1. Understand that biodiversity refers to the variety and variability of life forms within an ecosystem, including the number of species and their relative abundances.
2. Recognize that species richness is the count of different species present in the ecosystem, which gives a measure of how many types of organisms exist.
3. Understand species evenness, which describes how evenly individuals are distributed among the different species, indicating whether some species dominate or if all have similar population sizes.
4. Learn that biodiversity is most effectively measured by combining species richness and species evenness into a single value using diversity indices, such as the Shannon index, which quantifies both aspects.
5. Conclude that measuring total biomass, average body size, or counting only keystone species does not capture the full complexity of biodiversity as well as using species richness and evenness together.