Plants as drivers of rock weathering

The transformation of rock to soil affects the habitability of Earth because of its role in regulating climate and nourishing ecosystems. Soil formation has a strong biotic component because plants and associated microbes can influence the rate and trajectory of weathering processes. However, quantifying the effects of biota on weathering is challenging because such effects are interwoven with other biotic and abiotic influences. A need to resolve the role of vegetation in weathering is magnified by ongoing environmental change, which affects vegetation distribution and productivity. The changing environment is influencing plant interactions with rocks and biogeochemical cycles of rock-derived elements. Weathering processes also result in the removal of carbon dioxide from the atmosphere making plant enhancement of weathering a potential mechanism of carbon sequestration and therefore of interest as one of the mechanisms for climate mitigation. This chapter examines the mechanisms of plant enhancement of weathering and evidence of how it operates on different scales, micro, mesocosm, field, watershed, and global. We also discuss how global environmental change, including elevated temperatures, atmospheric CO₂, as well as agricultural practices are affecting plant enhancement of weathering. Finally, we conclude with questions that require further examination and a call for future directions of research.