An ecological survey compared the ground-dwelling invertebrate communities of two agricultural fields: an organic arable field and an intensive conventional monoculture field. The survey recorded a species richness of 15 in both fields, but the organic field was found to have a significantly higher Simpson's Index of Diversity.
Which of the following is a correct interpretation of these results?
The organic field has a higher species evenness, indicating a community that is more stable and less likely to be severely affected by environmental change.
The conventional field has a higher species evenness, meaning its invertebrate community is dominated by one or two highly abundant pest species.
The organic field has greater genetic variation within its individual invertebrate populations, allowing individual species to adapt faster to selective pressures.
The conventional field has a lower Simpson's Index because its total population size (NNN) is much larger, which mathematically reduces the diversity value.
24 exam-style questions on OCR A A Level Biology Biodiversity. Each one has a worked solution and a mark scheme showing where the marks go.