Trophic Cascade
A trophic cascade is a chain reaction through a food web, where a change at one feeding level ripples down through the levels below it.
Full definition of Trophic Cascade →:: COMPARE ::
Trophic cascadevsBottom-up control
The short 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.
Side by side
| Aspect | Trophic cascade | Bottom-up control |
|---|---|---|
| Direction | Top-down | Bottom-up |
| Driver | Predators | Water, nutrients |
| Yellowstone evidence | Weak | Plausible |
| Both real | Yes | Yes |
What each one means
Bottom-up control
The contrast above sets out how Bottom-up control differs from Trophic Cascade on the points that actually matter.