Trophic Cascade — Keystone Species Removal

Remove a keystone predator and watch cascading effects ripple through 3 trophic levels over time.

Species (click to remove)

t = 0 yr
Classic example: removing wolves from Yellowstone → deer/elk boom → overgrazing → vegetation collapse → soil erosion → beaver decline. The Lotka-Volterra cascade: ẋ₁ = r₁x₁ − a₁₂x₁x₂ (plants), ẋ₂ = −d₂x₂ + a₁₂x₁x₂ − a₂₃x₂x₃ (herbivores), ẋ₃ = −d₃x₃ + a₂₃x₂x₃ (predators). Keystone species have disproportionate impact relative to their biomass. Trophic cascade = indirect effects propagating downward.