Umar Farooq: Beyond Microbes: Integrating Termite-Mediated Decomposition into a Microbial-Explicit Soil Carbon Cycling Model
Beyond Microbes: Integrating Termite-Mediated Decomposition into a Microbial-Explicit Soil Carbon Cycling Model
Umar Farooq1, Chiara Pasut2, Ying-Ping Wang3, Bennett Macdonald1, Senani Karunaratne1
1 CSIRO Agriculture and Food, Canberra, Australian Capital Territory, Australia,
2 CSIRO Agriculture and Food, Waite Campus, South Australia, Australia,
3 CSIRO Environment, Clayton South, Victoria, Australia,
Microbial-explicit soil carbon models have improved the representation of soil organic carbon (SOC) dynamics by incorporating microbial-mediated decomposition and stabilisation processes alongside key soil properties. This mechanistic framework enables a more realistic simulation of SOC responses to environmental and anthropogenic perturbations than traditional first-order kinetic decomposition models. However, these models typically neglect the role of soil fauna, despite evidence that macro-fauna such as termites are major drivers of litter decomposition and carbon turnover in tropical and seasonally dry ecosystems. This omission contributes to uncertainty in the simulation of carbon cycling, soil carbon storage, and carbon-climate feedbacks.
Here we present a modified framework for incorporating termite-mediated decomposition processes into the Microbial Explicit Soil Carbon (MES-C) model. The proposed framework explicitly represents termite consumption of litter, interactions between termite and microbial decomposition pathways, and the partitioning of processed carbon among atmospheric emissions (CO2 and CH4), microbial substrates, and stabilised SOC pools. By linking termite activity to environmental drivers that control the biome-specific termite biomass distributions, the framework aims to capture an important but currently unresolved pathway in terrestrial carbon cycling.
Preliminary analyses suggest that termite-driven processing substantially alter decomposition rates, carbon residence times, and the balance between carbon storage and atmospheric release, particularly in tropical and semi-arid regions. Integrating termite-mediated pathways into microbial-explicit model provides a mechanism for representing faunal controls on decomposition and SOC formation, reducing uncertainties in terrestrial carbon cycling and improving predictions of soil carbon dynamics and greenhouse gas emissions in the next-generation land and Earth system models.