Fig. 4
Model ensemble predictions compared against observations. a the ΔCveg response to CO2 enrichment. The key variables leading to the response—b the cNPP response to CO2 enrichment and c dΔCveg/dcNPP. And the three components of dΔCveg/dcNPP—d fWa, e dfW/dcNPP and f cross-treatment mean cNPP. Coloured boxes and whiskers represent the model ensemble predictions (white bar is the median, the box the inter-quartile range, whiskers data within four times the IQR, and dots are outliers). Grey shaded areas represent the observations (dark grey lines are observed means or regression parameters, grey polygons are the SEM CI and the lighter grey polygons are the 95% CI). ORNL has no observed data on plots d and e as these were calculated from the regression of fW on cNPP. ORNL was not included as the regression was intended to explain the biomass retention rate, which was not significant at ORNL and was highly uncertain
