Process
Trophic cascade
Effects that ripple down a food chain, as when predators hold herbivores in check and plants flourish.
Keystone species
A species, often a predator, that strongly shapes its whole community. Robert Paine introduced the term in 1969.Source: Paine, 1969Source: Paine, 1966
Idea or model
How Keystone species connects
Keystone species can cause
Studied in
Your progress
Sources & further reading
The explanations on this page are our own summaries of these sources. Follow a link to read the original; if anything here disagrees with it, the original wins. How we choose and check sources.
A note on trophic complexity and community stability (opens the original in a new tab)
Paine RT (1969). The American Naturalist 103:91-93.
Introduced the term keystone species.
Historical paperPerspectiveFood web complexity and species diversity (opens the original in a new tab)
Paine RT (1966). The American Naturalist 100:65-75.
Removing a predatory sea star from rocky shores reduced the number of species present.
Historical paperPrimary research