Nonlinear Dynamics of a Nutrient-Phytoplankton Model with Time Delay

Figure 1

(a) The intersections between the vertical isocline and horizontal isocline with different nutrient concentrations , where the red solid line represents the horizontal isocline, the grey dashed line represents the asymptote of the horizontal isocline, and the other lines with different colors represent the vertical isocline that corresponds to different nutrient concentrations . (b) The stability of the positive equilibrium with the change in the nutrient concentration .

(a)

(b)