Trophic cascades occur when changes in the population of one species significantly affect the structure and dynamics of an ecosystem. Typically initiated by the removal or addition of top predators, trophic cascades can lead to dramatic consequences throughout the food web. For example, a decline in predators might result in overpopulation of herbivores, leading to overgrazing and a decline in plant diversity. Understanding these cascades is essential for effective ecosystem management, as they highlight the interconnectedness of species and the impacts of human activities on ecological balance.