What constitutes species diversity?

Species diversity refers to the variety of different species within a given area or ecosystem and includes both the number of species present and their relative abundance. This means that it encompasses not just how many species exist in a particular habitat, but also how evenly the individuals are distributed among those species. A high species diversity indicates a balanced ecosystem where no single species dominates, which can contribute to ecosystem stability and resilience.

The other options focus on different but related aspects of biodiversity and ecological health. The variety of habitats in an ecosystem refers to habitat diversity, which is important in supporting species diversity but is not the same concept. The total biomass of species in an area measures the mass of living organisms but does not provide insight into the number of species or their distribution. Lastly, genetic variability within a species pertains to genetic diversity, which is crucial for the adaptability and survival of species but is distinct from the concept of species diversity. Therefore, the correct understanding of species diversity centers on both the richness of species and their population distributions in an ecosystem.