Figure 5
From: Extreme climatic events down-regulate the grassland biomass response to elevated carbon dioxide
Relationships between the killing degree days (KDDs) and the effect size (ES) of grass biomass in the summer harvest (H2). To remove the side effects of extreme [CO2] enrichment events in 2012 and 2013, only the early 14 years data (1998–2011) were used for this figure. (a) Time series of KDDs (red curve, refer to right axis) and the ES (black curve, refer to left axis). (b) Regression analysis, 28% variance of the natural logarithm effect size can be explained by the natural logarithm KDDs, which is significant with p = 0.031. For the results without logarithmic transformation, please refer to Fig. S14.
