1. (a) (b) Fig. S1 Monthly rainfall (mm mo -1 ) measured at (a) TNF from 2002 to 2004 and (b) CAX from 2001 to 2008 (red line and symbols). The black line and shaded area shows long-term (>30 years) precipitation patterns (mean±stdev.) for each site reported by Rosolem et al. (2008).

2. (a)(b) TNFCAX Fig. S2 Change in aboveground biomass (AGB, kg C m -2 ) with an 80% reduction (d80) in precipitation relative to the control (d0) simulations shown in Fig. 1. Colored lines are individual model predictions and black line is the 5 model ensemble mean. Shaded area is the 95% CI of the models. (a) Tapajós National Forest. (b) Caxiuanã National Forest.

3. (a) (b) Fig. S3 Time series of published periodic measurements of soil respiration (R s ) for CAX (Sotta et al., 2007) and concurrent individual model estimates for the (a) control (d0) and (b) treatment (d50) plots of CAX. Color lines are individual model predictions and the black line is the 6 model ensemble mean. Shaded area is the 95% CI of the models. d0 and d50 are drought levels indicating a 0% and 50% reduction in precipitation. The  plot (b) shows the amount the control (a) R s was altered by the 50% drought treatment.

4. (a)(b) (c) (d) TNFCAX (g) (f)(e) (h) Fig. S4 Annual gross primary production (GPP, kg C m -2 yr -1 ) for TNF (left side) and CAX (right side). Colored lines are individual model predictions and the black line is the 6 model ensemble mean. Shaded area is the 95% CI of the models. Drought levels are indicated by d30, d50 and d80, which are respectively 30%, 50% and 80% reductions in precipitation. The  indicates the amount the d0 carbon fluxes were altered by the indicated drought level.

5. (a)(b) (c)(d) TNFCAX (g) (f)(e) (h) (i)(j) Fig. S5 Full 7 year time series of the monthly mean water-stress factor (  ) for (a, b) CLM3.5, (c, d) ED2, (e, f) IBIS, (g, h) JULES, (i, j) SiB3 at each treatment level (colored lines) for TNF (left side) and CAX (right side).

6. (a)(b) (c) (d) TNFCAX (g) (f)(e) (h) Fig. S6 Annual heterotrophic respiration (R h, kg C m -2 yr -1 ) for TNF (left side) and CAX (right side). Colored lines are individual model predictions and the black line is the 6 model ensemble mean. Shaded area is the 95% CI of the models. Drought levels are indicated by d30, d50 and d80, which are respectively 30%, 50% and 80% reductions in precipitation. The  indicates the amount the d0 carbon fluxes were altered by the indicated drought level. Insets in (g) and (h) show full range for CLM3.5.

7. (a)(b) (c) (d) TNFCAX (g) (f)(e) (h) Fig. S7 Annual autotrophic respiration (R a, kg C m -2 yr -1 ) for TNF (left side) and CAX (right side). Colored lines are individual model predictions and the black line is the 6 model ensemble mean. Shaded area is the 95% CI of the models. Drought levels are indicated by d30, d50 and d80, which are respectively 30%, 50% and 80% reductions in precipitation. The  indicates the amount the d0 carbon fluxes were altered by the indicated drought level.