The correct answer is: Keystone species.
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. When these species are removed from an ecosystem, there can be a significant cascade effect, with many other species also being affected.
For example, the removal of sea otters from kelp forests can lead to an increase in the population of sea urchins, which eat kelp. This can lead to the collapse of the kelp forest ecosystem, which would have a knock-on effect on many other species that rely on the kelp for food or shelter.
Keystone species are often predators, as they can control the populations of other species. However, they can also be herbivores, decomposers, or even plants.
Some examples of keystone species include:
- Sea otters in kelp forests
- Wolves in Yellowstone National Park
- Beavers in North American forests
- Elephants in African savannas
Keystone species are important because they help to maintain the balance of an ecosystem. When they are removed, the ecosystem can become unbalanced, which can have a negative impact on many other species.
It is important to protect keystone species, as they play a vital role in the health of our planet.