Soil Biogeochemistry Models Omit Key Processes Due to Geographic Bias

A comparison of modeled and observed soil organic carbon (SOC) stocks for three commonly used soil biogeochemistry models (a-c). Each panel reports model performance metrics generated with “default” model parameters and with parameters informed by observations (“fitted”). While model performance tends to increase with fitted parameters, all three models poorly predicted SOC stocks in Sub-Saharan Africa. Credit: von Fromm et al. [2026], Figure 1