Figure 1
From: Complementary mechanisms stabilize national food production
Structural equation model representing the drivers of the stability of national food production. For a seek of clarity, the contribution of agricultural inputs (red path) and crop diversity (blue path) to the stability of national food production are represented separately from the ones of climate variability (green path) [left and right panels, respectively]. Top: Non-weighted model. Crop diversity is quantified by crop richness. Down: Abundance weighted-model. Crop diversity is quantified by the exponential of Shannon diversity index. Asynchrony and average stability are weighted by the proportion of total cropland each crop occupied. The thickness of the arrows indicates the relative contribution of each variable. Plain arrows represent positive relationships while dotted arrows represent negative relationships between two boxes. Only relationships supported by the data (P > 0.05) are shown. Standardized regressions weights (along arrows) and squared coefficient of regressions (r2) for the fitting model are shown. Test indicates close model-data fit (Fisher’s C = 0.16, P = 0.92 and Fisher’s C = 0.46, P = 0.79 for non-weighted and weighed models, respectively). National yield stability, nitrogen use intensity and the percentage of land equipped for irrigation are log-transformed.
