Figure 4
Scatter plot of response ratio of yield (RRY) to water input when mean annual temperature (MAT) is (a) <8 °C, (b) 8–15 °C, or (c) >15 °C; to nitrogen input when MAT is (d) <8 °C, (e) 8–15 °C, or (f) >15 °C. Response ratio stands for effect size between the treatment and control and is calculated using Eq. 2. The solid black line represents the weighted regression line based on variance-weighted least squares. The grey line shows the 95% CI around the regression line. The circles indicate the response ratio of each observation. The circle size is proportional to the precision of the response ratio. Note the different scales among the graphs.
