Question 1

What is the difference between Trophic cascade and Bottom-up control?

Accepted Answer

A trophic cascade is top-down: predators structure the levels beneath them. Bottom-up control runs the other way — nutrients, water and plant productivity set what the system can support. Yellowstone is the case study for why you can't assume top-down, since hydrology may outweigh the predator signal entirely.

Question 2

How do I know if I mean Trophic Cascade rather than Bottom-up control?

Accepted Answer

Readers who land here meaning Trophic Cascade rather than Bottom-up control are usually searching for phrases like “did wolves change the rivers in yellowstone”, “what is a trophic cascade”, “yellowstone wolves story true”.

Aspect	Trophic cascade	Bottom-up control
Direction	Top-down	Bottom-up
Driver	Predators	Water, nutrients
Yellowstone evidence	Weak	Plausible
Both real	Yes	Yes

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Trophic Cascade

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