Vegetation‐Promoted Soil Structure Inhibits Hydrologic Landslide Triggering and Alters Carbon Fluxes

Abstract

Abstract Vegetation modulates rainfall‐induced shallow landslides in mountainous regions primarily via root reinforcement, canopy interception, and evapotranspiration. An understudied consequence of vegetation activity is the promotion of soil structure development—an important soil trait often neglected in hydromechanical models. Here we propose a novel mechanism for how vegetation‐promoted soil structure inhibits landslides via enhanced hillslope infiltration capacity and drainage that delay the onset of landslide triggering. The hydrologic alterations due to developed soil structure also decrease sediment yields and associated particulate organic carbon (POC) transport to rivers while promoting export of dissolved organic carbon (DOC) via hydrologic leaching. We identified global “hotspots” for soil structure impacts that support the putative role of vegetation‐promoted soil structure in observed POC/DOC partitioning. The incorporation of soil structure in Earth system models is not only important for infiltration‐runoff quantification, but also for its potential role in controlling regional and global carbon fluxes to oceans.

Keywords

• landslide triggering
• soil structure
• hydraulic conductivity
• carbon flux