Question

Both keystone and foundation species are critical to ecosystem function. What are key differences between these two categories of species? Do some research on your own about different types of keystone and foundation species, and describe an example of each. What would happen if these species were eliminated? Discuss.

Answer 1

A keystone species in an ecosystem is that species which has profound effect on the ecosystem. It might not be the largest species but its presence and role within the ecosystem has a disproportionate effect on other organisms within the system. Without them, the ecosystem would change or suffer. It is believed that the keystone species help to increase biodiversity of communities by preventing a single species from becoming dominant. Thus, they have a profound effect on the balance of organisms in a particular ecosystem. Some examples are bisons, otters, prairiie dogs, elephants, etc. When elephants eat vegetation, they creat clearings which help in tree regeneration in forests.

A foundation species is that which has a strong role in structuring an ecosystem. It can occupy any trophic level, that is, it can be producer, primary consumer, secondary consumer or decomposer. Foundation species help to creat and maintain a habitat that supports other species. Some examples of foundation species are coral reefs, earthworms in the soil, and many more. Earthworms help to make the soil rich in humus as well as create air spaces which helps in healthy growth of plants. Coral reefs are the breeding and hunting grounds for so many other sea organisms.

Both, keystone as well as foundation species are essential for maintaining a healthy, dynamic and flourishing ecosystem. Any disturbance in their population will have a negative impact on the balance within the habitat. If the disturbance is acute then the entire structure of the ecosystem might change and may even cause the collapse of the structural balance within the ecosystem.