Practice question

The keyed exception is “Influence proportional to abundance.” In the context of incorrect statement about keystone species, that statement differs from the governing ecological pattern and must be evaluated against the mechanism rather than accepted from wording alone. Management outcomes depend on scale and context: suppressing abundance at one site does not guarantee regional eradication when dispersal reconnects treated and untreated populations. The remaining alternatives—“Species other than consumers can be keystone”, “Removal reduces species richness”, “Removal causes trophic cascades”—refer to different states, processes, or scales and therefore do not express the same causal relationship. 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. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation.