Unveiling How Climate Warming Alters Soil Organic Carbon Transformation: Insights from Microorganisms

Abstract

Global climatic shifts significantly affect the functionality of terrestrial ecosystems, with soil organic carbon (SOC) being vital for sustaining their productivity and long-term viability. The excessive release of greenhouse gases, predominantly CO₂, has triggered ongoing global warming. Microorganisms act as the driving force behind SOC turnover and serve as critical intermediaries through which warming influences SOC storage and chemical traits. While climate warming has led to a reduction in organic carbon stores in most farmlands and forests, grasslands have seen an increase in organic carbon levels. This discrepancy is likely tied to the balance between microorganisms' breakdown of organic carbon for energy and their conversion of it into stable forms.

Rising temperatures, coupled with higher atmospheric CO₂, boost plant growth and photosynthesis, thereby increasing the input of organic carbon into soils. These external carbon sources are transformed by microorganisms into stable reserves, which in turn enhance microbial respiratory activity. This process shifts the microbial community toward a higher proportion of bacteria relative to fungi, negatively impacting soil carbon storage. Plant functional groups (PFGs) facilitate the release of labile organic carbon from soils and accelerate the rate at which microorganisms mineralize carbon.

When evaluating how agroecosystem multifunctionality (EMF) responds to these changes, both microbial diversity and their interactions must be considered—this is key for forecasting shifts in ecosystem functions under future climate scenarios. Gaining a comprehensive understanding of the climate-microbe-SOC relationship from multiple angles will help maximize the soil's carbon sequestration potential amid global changes.