Moisture-driven divergence in mineral-associated soil carbon persistence.

Mineral stabilization of soil organic matter is an important regulator of the global carbon (C) cycle. However, the vulnerability of mineral-stabilized organic matter (OM) to climate change is currently unknown. We examined soil profiles from 34 sites across the conterminous USA to investigate how the abundance and persistence of mineral-associated organic C varied with climate at the continental scale.

Climate Effects on Subsoil Carbon Loss Mediated by Soil Chemistry.

Subsoils store at least 50% of soil organic carbon (SOC) globally, but climate change may accelerate subsoil SOC (SOC) decomposition and amplify SOC-climate feedbacks. The climate sensitivity of SOC decomposition varies across systems, but we lack the mechanistic links needed to predict system-specific SOC vulnerability as a function of measurable properties at larger scales. Here, we show that soil chemical properties exert significant control over SOC decomposition under elevated temperature and moisture in subsoils collected across terrestrial National Ecological Observatory Network sites.