What does the term "trophic cascade" refer to?

The term "trophic cascade" refers to an ecological phenomenon that occurs when the addition or removal of top predators significantly impacts the structure and population dynamics of lower trophic levels in an ecosystem. This concept highlights the interconnectedness of different species within a food web. For instance, when a top predator is removed, it can lead to an overpopulation of herbivores, which in turn may overgraze vegetation. This can reduce plant diversity and impact other species that rely on those plants for habitat or food. Conversely, the reintroduction of a top predator can help control herbivore populations, allowing vegetation to recover and promoting biodiversity within the ecosystem.

This cascading effect illustrates the importance of top predators in maintaining the balance of ecosystems and demonstrates how changes in one part of the food web can ripple through to affect many other organisms and their environments.