Plant and mycorrhizal driven silicate weathering: Quantifying carbon flux and mineral weathering processes at the laboratory mesocosm scale

The rise of vascular land plants in the Paleozoic is hypothesized to have driven lower atmospheric CO₂ levels through enhanced weathering of Ca and Mg bearing silicate minerals and rocks. However, this view overlooks the co-evolution of roots and mycorrhizal fungi, with many of the weathering processes ascribed to plants potentially being driven by the combined activities of roots and fungi. Here mesocosm scale controlled laboratory experiments quantifying the effects of plant and fungal evolution on silicate rock weathering under ambient and elevated CO₂ concentrations are described. A snapshot is presented of C allocation through roots and mycorrhizal fungi and biological activity associated with geochemical changes in weathered mineral substrates via transfer of elements from solid phases into solution.