Landsliding and rhizobiota link the short- and the long-term carbon cycle through silicate rock weathering

Abstract

The microbial community inhabiting the root-soil contact interface, rhizobiomes, represent a critical link between plant, ecosystems, and geomorphic processes. In landslides where fresh silicate rocks are exposed, rhizobiomes may set in motion several biogeochemical transformations with local to global impacts. Given the prevalence of landslides in humid mountains wordwide and the understudied role of rhizobiomes in these environments, I designed a field study to address two aims: 1) characterize the composition, and function of plant rhizobiomes established in “landslide-like” areas, and 2) evaluate the role of rhizobiomes in (Ca,Mg)-silicate rock weathering through an rock incubation experiement. I found two key results: 1) that the distinctive biotic and abiotic factors between landslides and forests habitats were important in structuring microbial community composition and functioning, and 2) that rock weathering occurrs faster in landslides compared to forest, and that the resulting nutrient mobilization drives microbial diversity and composition.