Which of the following describes a keystone species? Select ALL that apply.
A highly abundant grass species in the prairies of the Midwest, United States. Removal of this particular grass species resulted in an increased abundance of other herbaceous plant species and had no effect on herbivore abundance or diversity.
Beavers which drastically alter riparian habitats by damming rivers, creating ponds and lakes.
An uncommon sea star species found in the Pacific Northwest coastal zones. This sea star feeds on mussels which become highly abundant when the sea star is removed from the habitat. Musses will outcompete other invertebrates for space, reducing overall species richness in the habitat.
Burmese pythons which were introduced to the Florida Everglades in the 1980s. Since then, they have become a devastating invasive species as their population in Florida has skyrocketed due to a lack of predators and competition.