What is the likely impact on community diversity when keystone species are removed?

When keystone species are removed from an ecosystem, it typically leads to a decreased diversity within the community. Keystone species play a crucial role in maintaining the structure and function of their ecological community. They often influence the types and numbers of various species present. The removal of such a species can disrupt these relationships, often resulting in a domino effect where other species either decline or disappear entirely.

For example, if a top predator is removed, populations of herbivores may increase unchecked, leading to overgrazing and a resulting decline in plant diversity. Similarly, if a species that provides critical habitat or food sources is lost, other dependent species may also suffer. Consequently, the overall complexity and richness of species in the community can diminish, leading to decreased diversity.

In contrast, an increase in diversity or no impact would suggest a stability that isn't typical when a keystone species is absent, reflecting a misunderstanding of the critical roles these species play in ecosystems. Minor fluctuations might occur, but generally, the removal of a keystone species tends to result in more significant changes, thus overwhelmingly pointing to a decrease in diversity.