Interfacing plant and soil in earth system models: Missing components and implications

Fertilization of terrestrial plants by elevated CO₂ concentrations is an important component of Earth’s greenhouse gas budget and strongly affects climate change predictions. Substantial changes have been documented at the plant-soil interface (e.g., rhizosphere enzymatic activity and mycorrhizal fungi), which provide possible explanations to the observed plant and soil dynamics under elevated CO₂ conditions. Unfortunately, representations of the rhizosphere and mycorrhizae are absent in current ESMs. To address this issue, we built a plant-soil interface model for integration in the ACME Land Model (ALM) to explain the observed changes of soil nitrogen dynamics at Oak Ridge and Duke FACE sites.