Which factor determines the richness of species in an ecosystem?

The richness of species in an ecosystem is influenced significantly by various ecological interactions and the inherent characteristics of the organisms present, including their sensitivity to changes within the ecosystem. This sensitivity refers to how organisms and communities respond to environmental factors, disturbances, and changes in their habitat. Ecosystems with high sensitivity often exhibit more complex interactions among species, which can enhance biodiversity.

For example, ecosystems that evolve together over long periods tend to have species that are well-adapted to each other, fostering a rich variety of life forms. Additionally, sensitive species can act as indicators of ecosystem health, reflecting the quality and stability of their environment. When these species thrive, they contribute to overall species richness. Therefore, while the other factors listed—such as age, geographical location, and rainfall—play roles in biodiversity, it is the intricate relationships and sensitivities among species that play a pivotal role in determining the richness of species in an ecosystem.