What does an indicator species help determine in an ecosystem?

An indicator species is a type of organism that provides insight into the health of an ecosystem, particularly in relation to environmental conditions. The primary role of an indicator species is to signal the level of pollution within a habitat. These species are sensitive to changes in their environment and can reflect the impacts of pollutants such as heavy metals, chemicals, or changes in pH. When the population of an indicator species declines or changes in health, it serves as a warning that the ecosystem is experiencing stress due to pollution.

For example, certain species of lichen are known to be sensitive to air quality; their presence often indicates clean air, while their absence may suggest higher levels of air pollution. Similarly, in aquatic environments, specific species of fish or invertebrates can indicate levels of water pollution or changes in water quality.

While species diversity, conservation status, and predator-prey relationships are important aspects of ecosystem dynamics, they do not specifically indicate pollution levels in the same way that indicator species do. Thus, understanding the role of indicator species is crucial for assessing the health of an ecosystem and determining the impact of pollution on the environment.