Gooding (2026): Geochemistry of carbon sequestration through woody biomass burial
James L. Gooding, IN: Geosciences, https://www.doi.org/10.3934/geosci.2026003
Apparent mechanisms and rates of wood decay under natural geologic burial can be reconciled with general principles of chemical thermodynamics and kinetics, including effects of biotic intermediaries on reaction pathways. A simplified two-step decay model for woody biomass burial (WBB) involves the hydrolysis of wood biopolymers to release monomers, which then decompose into CO₂ or CH₄. Gibbs free energy values for individual reactions indicate that (a) biopolymer hydrolysis follows a stability sequence of lignin >> cellulose > hemicellulose, and (b) monomer decomposition is driven more strongly toward CO₂ (compared with CH₄) unless biological intervention occurs. Key variables are wood composition, water activity, oxygen activity, and enzymatic activity (from bacteria or fungi) under different burial conditions.