What is the role of a keystone species in an ecosystem?

A keystone species plays a crucial role in maintaining the structure and stability of an ecosystem. This species, although often not the most abundant, has a disproportionately large impact on its environment relative to its abundance. By contributing to the diversity and complexity of the ecosystem, keystone species keep populations of other species in check, which helps to prevent any one species from dominating and allows for a healthy balance among various organisms.

For instance, a keystone predator may regulate the population of prey species, thereby benefiting plants and other organisms that would otherwise be overgrazed or overbrowsed. In this way, the presence of a keystone species is essential for the prevention of ecosystem collapse, as it supports biodiversity and the interactions among different species. This foundational role ensures that energy flow, nutrient cycling, and habitat structure are maintained effectively within the ecological community.

Other options may imply functions that are not aligned with the fundamental characteristics of keystone species. For example, outcompeting all other species or acting solely as a predator suggest a singular influence that doesn't encapsulate the broader supportive role necessary for ecosystem health. Additionally, serving purely as a primary producer doesn't align with the definition of keystone species, which often include predators, prey, and plants that facilitate