Ideas and perspectives: Beyond Microbes: Integrating Termites into Global Soil Carbon Cycling Models
Abstract. Termites are major detritivores in tropical and subtropical ecosystems, yet their contributions to the terrestrial carbon cycle remains absent from process-based soil organic carbon (SOC) models. Here, we present a termite carbon module that explicitly represents termite-mediated litter consumption and transfer of ingested carbon into gaseous (CO2, CH4) and SOC pools. The module integrates biome-specific termite biomass with spatially explicit productivity inputs to quantify termite-driven carbon fluxes within a mass-balance framework. Model simulations show that termites act as spatially heterogeneous carbon processors, accelerating litter turnover while modifying the pathways through which carbon is redistributed between atmospheric and SOC pools. Global sensitivity analysis identifies termite biomass and ingestion capacity as the dominant controls on flux magnitude, whereas carbon partitioning governs the fate of processed carbon. Including termite-mediated pathways in SOC models provides a mechanism for representing faunal controls on decomposition, soil carbon formation, and trace gas emissions, particularly in tropical and seasonally dry ecosystems. Globally, we estimate termites process 1569.4 ± 800.4 Tg C yr-1, releasing 864.7 ± 444.5 Tg C yr-1 as CO2 and 7.9 ± 4.9 Tg C yr-1 as CH4, while transferring 689.3 ± 367.4 Tg C yr-1 into labile and mineral-associated SOC. Explicit representation of termite-driven carbon fluxes will therefore be important for improving predictions of litter decomposition, SOC formation, and terrestrial carbon-climate feedbacks.