Fig. 4: Functional trait diversity-mediated changes in future above-ground biomass.

Predicted change in above-ground biomass between 1990 and 2100 for RCP4.5 with and without increasing CO₂. A, B Predicted percentage change in biomass as mediated by functional trait diversity (Rao’s quadratic entropy). Changes are shown at varying levels of precipitation reduction by 2100. A, B Predictions with increasing CO₂. C, D As in (A) and (B) but with CO₂ held constant at 1990 levels. Predictions are based on a linear mixed effects model (Table S6). Lines are predicted mean responses for the effect of functional diversity on change in above-ground biomass at varying levels of precipitation reduction. Shading indicates a 95% confidence interval. The range of values for precipitation reductions was based on the approximate mean reduction for the study area of 30% (Fig. S2B, C) up to a value of 50% consistent with site-level drought experiments. See “Amazonian climate change scenario simulations—Plant strategy removal” and Table S6 for further details. 2T indicates that RaoQ was calculated using 2 traits (P50 and Root-D). The data underlying this figure are provided in figshare (https://doi.org/10.6084/m9.figshare.26232395).