Figure 4c: C. Phase space diagram of system (Eq.1, Eq.2, Eq.3). This figure shows that with any initial concentration of (DIC, P, Z) which is denoted by blue bullet, system converges to coexistence equilibrium point * E*2 DIC ,P2 ,0 ) which is indicated by red bullet. Parameter are: rphy=1.24; rzoo=0.25; P_psyn=2; k_DIC=1.5; r_cp=0.43; l_rt1=0.09; g_rt=0.6; k_z=0.1; m_rp=0.03; l_rt2=0.01; p_rz=0.22; r_ex=0.01; m_rz=0.05; l_rt3=0.1; I=10; s_e=3.32; s_r=1.64.