Impacts of trophic interactions on carbon accrual in soils

The transformation and stabilization of soil organic carbon (SOC) are important processes of global carbon (C) cycling, with implications for climate change. Much attention has been given to microbial anabolic processes driving SOC accrual. These are referred to as the soil microbial carbon pump (MCP), which emphasizes the contribution of microbial metabolism and necromass to the stable soil C pool. However, we still lack a fundamental understanding of how trophic interactions between soil fauna and microbiota modulate microbial necromass production and, consequently, SOC formation. Here, we provide an ecological perspective on the impacts of trophic interactions on modulating necromass formation and C accrual in soils. We discuss the mechanisms of trophic interactions in the context of food web ecology, with a focus on trophic control of microbial population densities and their influences on soil microbiota assembly. We foresee that integrating trophic interactions into the soil MCP framework can provide a more comprehensive basis for guiding future research efforts to elucidate the mechanisms modulating microbial necromass and SOC formation in terrestrial ecosystems. This perspective offers an ecological foundation for leveraging the use of biological interventions to enhance SOC accrual, providing valuable insights for sustainable C management strategies.