Continuable Weathering of Silicate Minerals Driven by Fungal Plowing

Abstract

Silicate weathering acts as a significant carbon sink and sustains ecosystems by supplying essential elements, thus shaping Earth's habitability. However, our understanding the evolution of silicate weathering rates remains incomplete, with most knowledge focusing on rate decreases at solution-silicate interfaces, while reactivity at fungi-weathered silicate interfaces is poorly understood. This study shows that the fungus Talaromyces flavus significantly enhances the dissolution of olivine and lizardite covered by Si-rich layers up to 3.6 μm thick by one to two orders of magnitude compared to abiotic conditions. Initially, fungal hyphae create dissolution channels ∼10–65 nm deep, promoting element release from altered layers and underlying pristine minerals while oxidizing structural Fe(II). Over time, hyphae penetrate these altered layers, exposing and etching the underlying minerals. Our data suggest that fungal etching and penetration degrade the altered layers, leading to increased interdiffusion of weathering agents and released cations, thereby continuously driving silicate weathering.