Summary effect sizes during and 1–7 years after biomanipulation. Means based on the selected dataset are shown during manipulation (D) and 1–3 years after manipulation, and also for each of the first 7 years after manipulation. Vertical lines indicate 95% confidence intervals. Numbers of biomanipulations with data are indicated in the upper part of the panels. ‘Before’ and ‘During’ periods have been defined as in Figures 5 and 6. Forest plots showing all individual effect sizes are presented in Additional file 10 (pp. 19–22).