Fig. 6From: Response of chlorophyll a to total nitrogen and total phosphorus concentrations in lotic ecosystems: a systematic reviewMeta-regression plots showing the influence of mean nutrient concentration on effect size for the four stressor-response relationships. Effect size is plotted as Z-transformed Pearson correlation. Each circle is an effect size with the diameter representing total variance. Solid black line is the linear regression line and dotted black lines are 95% confidence interval. Red line is the LOESS curveBack to article page