What role do keystone species play in an ecosystem?

Keystone species play a critical role in maintaining the structure of an ecosystem due to their unique influence on the environment and the organisms within it. These species contribute to ecological balance and stability, often regulating the populations of other species and helping to shape the habitat itself. For instance, a predator that controls the population of herbivores can prevent overgrazing, allowing plant communities to thrive, which in turn supports a diversity of other organisms.

The concept of a keystone species highlights that some species exert a disproportionately large effect relative to their abundance. While not necessarily the most numerous, their presence or absence can significantly alter community dynamics and biodiversity. This distinguishes them from other species that may not have such a pivotal role in their ecosystems. Keystone species can be found in both terrestrial and aquatic environments, underlining their importance across various ecosystems. Their critical contributions are essential for maintaining ecosystem health and resilience.