Meaning & use
keystone species
Last updated
Meaning
nouncountabletechnicalbiology
A species that has a very large effect on its ecosystem compared to its numbers.
Grammar: Countable; plural is also 'keystone species'.
Patterns
- a keystone species in an ecosystem
- a keystone species of a habitat
The sea otter is a keystone species because it controls sea urchin populations.
Wolves are considered a keystone species in Yellowstone National Park.
Word forms
| plural | keystone species |
|---|
Common combinations
- a keystone species in
- Beavers are a keystone species in wetland ecosystems.
- play a keystone role
- Elephants play a keystone role in savanna ecosystems.
- act as a keystone species
- Fig trees act as a keystone species in tropical forests.
Commonly confused: keystone species or dominant species?
keystone species vs dominant species
Dominant species are the most abundant, while keystone species have a large effect despite low numbers.
Practice
Which statement about a keystone species is true?
Choose one answer.
A keystone species has a large effect relative to its abundance. Option An is false because it may be rare. Option C is about size, not ecological impact. Option D is not necessarily true; endangered status is separate.
Make it your own
Write a sentence using “keystone species”, then check it and compare it with the examples above.