What is a trophic cascade in an ecosystem?

A trophic cascade refers to the ripple effects that occur in an ecosystem when top predators are added or removed. The concept is based on the interconnectedness of food webs, where changes at the top of the food chain can have significant downward effects on lower trophic levels.

When top predators are removed, there is usually an increase in the population of their prey species. This can lead to overgrazing or overpopulation of those prey, resulting in a decrease in plant biomass and potentially the collapse of certain habitat ecosystems. Conversely, if top predators are introduced, they can help control prey populations, thereby allowing plant communities to thrive and maintain a balanced ecosystem. This phenomenon highlights the importance of top predators in maintaining ecological balance and demonstrates how alterations in predator populations can have widespread effects on biodiversity and the stability of ecosystems.

The other options describe different ecological concepts that do not directly relate to the cascading effects of predator dynamics within food webs. For instance, the introduction of invasive species can disrupt ecosystems but does not specifically pertain to the interactions described by trophic cascades. Seasonal breeding patterns and biodiversity measurement methods also focus on different aspects of ecological study and do not illustrate the direct interaction between predator and prey populations.