Species group whose removal triggers cascades:
“Keystone species” for species group whose removal triggers cascades. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Species management must identify the demographic stage and ecological process that most strongly limits population growth. Prevention, early detection, removal, habitat manipulation, and biological control act at different points in an invasion or recovery trajectory. The remaining alternatives—“Indicator species”, “Generalist species”, “Specialist species”—refer to different state
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 21