What key observation suggests scientists are witnessing a trophic cascade rather than simple dynamics?

Answer

Researchers observe a non-linear response in the producer population relative to changes at the top.

A trophic cascade is often suspected when the response in the producer population is non-linear; for instance, if elk numbers are halved but willow growth triples.

What key observation suggests scientists are witnessing a trophic cascade rather than simple dynamics?
EcologyEcosystemPredatortrophic cascadefood web