Every trophic transfer loses most of the incoming energy to respiration (metabolic heat), incomplete digestion, and unconsumed biomass. Only a small fraction — the trophic (ecological) efficiency η — passes to the next level. Lindeman's Rule sets η ≈ 10% as a rough ecosystem average (real values range ~5–20% depending on taxa and ecosystem):
E(n) = E₀ · η^n
E₀ = producer energy input (kcal m⁻² yr⁻¹)
η = trophic transfer efficiency (fraction, e.g. 0.10)
E(n) = energy available at trophic level n
Because loss compounds multiplicatively, a chain of 5 levels at η=10% retains only 0.01% of the original energy (a 10,000× dilution) — which is why food chains rarely exceed four or five levels: beyond that point there is not enough energy left to support a viable population of a new predator.
- η slider — sets the fraction of energy that survives each transfer; the pyramid narrows faster at low η and flattens out at high η.
- E₀ slider — sets how much energy producers fix at the base (varies hugely by biome: rainforests and estuaries sit near the top of the range, deserts and open ocean near the bottom).
- Levels slider — how many trophic levels are rendered; a level whose energy has fallen below the 1 kcal m⁻² yr⁻¹ viability floor is drawn dim and grey.
- Rising particles are individually sampled: each one either survives a transfer (green, continues climbing) or is consumed as heat/waste at that boundary (flares orange-red and dissipates) — the aggregate ratio of survivors to losses converges on η exactly as the formula predicts.
- The lower chart plots E(n) on a log scale across levels — a straight declining line is the visual signature of the exponential decay E₀·η^n; drag the pyramid to pan, scroll/pinch to zoom.