Extended Data Fig. 5: Omitting measures of water supply biases estimated effects of temperature on crop yield in simulation.
From: More accurate specification of water supply shows its importance for global crop production
(A) Simulated daily temperature and soil moisture. (B) Estimated temperature response curves where simulated yields are a linear function of daily growing season temperature and soil moisture. The prescribed true response (black) is shown along with estimated responses modelling temperature (red), temperature and precipitation (yellow), and temperature and soil moisture (blue). (C) Similar response curves to (A) except that yield is simulated and modelled as a quadratic, rather than linear, function of temperature. (D) Similar to (C) except that instead of soil moisture having a linear influence on yield, soil moisture has a nonlinear influence whereby increasing soil moisture at low values increases yield but increasing soil moisture at high values has little effect. This produces larger bias at high temperatures than at low temperatures in the models that omit soil moisture, which is consistent with what we observe in Fig. 2. (E) Similar to (A) but with a stronger simulated relationship between daily soil moisture and temperature in hot and dry conditions. (F) Similar to (D) but with additional bias at high temperatures relative to low temperatures due to the strengthened soil-moisture temperature relationship in (E).
