Ecological Stoichiometry

Redfield Ratio C:N:P = 106:16:1 · Droop Model · Nutrient Cycling

C:P ratio
106
Redfield: 106
N:P ratio
16
Redfield: 16
C:N ratio
6.6
Redfield: 6.6
Limiting nutrient
N
Liebig's Law
10.0
0.60
50
Redfield's discovery (1934): Ocean phytoplankton maintain a near-constant elemental ratio of C:N:P = 106:16:1 (by atoms). This matches deep ocean dissolved nutrients — implying life sets ocean chemistry over geological timescales. The Droop model captures luxury uptake: growth rate μ = μmax(1 − Qmin/Q) where Q is internal quota. Liebig's Law of the Minimum: only the most limiting nutrient controls growth. N-limitation → excess P released; P-limitation → N accumulates in water.