Fig. 2. The stability properties of Equilibrium E1 (APB dominate) and Equilibrium E2 (cyanobacteria dominate) depend on the input rate of iron(II), f1, and the input rate of phosphate, f2.
High values of f1 and low values of f2 promote stability of E1 and instability of E2. Low values of f1 and high values of f2 promote instability of E1 and stability of E2. a If the proportional consumption rate of oxygen, b, is large, then intermediate values of f1 and f2 lead to both E1 and E2 being unstable, with Equilibrium corresponding to stable coexistence. b For an intermediate value of b, either E1 is stable with E2 unstable, or E1 is unstable with E2 stable. c If b is small, then intermediate values of f1 and f2 lead to both E1 and E2 being stable.