Figure 4.

Linear regressions between resource nitrogen to phosphorus (N:P) and Microcystis bloom N:P (A) and microcystin-LR cell quota (fg cell⁻¹); (B) separated by P concentration. (20 µg L⁻¹ P, orange circle; 40 µg L⁻¹ P, green triangle; 80 µg L⁻¹ P, blue square; 175 µg L⁻¹ P, cyan diamond; 350 µg L⁻¹ P, black triangle; and 700 µg L⁻¹ P, grey hexagon). Relationships between Microcystis N:P and microcystin cell quotas separated by P concentration (C). Regression equations and significant differences in slope are found in Table 1. Slopes of resource N:P and Microcystis N:P related to resource P concentrations with 95% confidence intervals (D). Slopes of Microcystis N:P and microcystin cell quota related to resource P concentrations with 95% confidence intervals (E). Slopes of resource N:P and Microcystis N:P regressed against slopes of Microcystis N:P and microcystin cell quota with 95% confidence intervals (F).