Abstract
Peat fires are catastrophic, causing severe, irreversible carbon and biodiversity loss. The subtropical wire-rush (Empodisma minus) peatswamps of coastal Queensland, Australia, overturn this paradigm — not only resisting and recovering from repeated fire, but requiring fire to thrive and sustain their exceptional carbon stores. Since 2023, we have been investigating the impacts of fire on peatswamp ecosystem functioning through flora and fauna surveys, peat coring (examining physico-chemistry, carbon sequestration, microbiology, fire history, plant succession), decomposition studies, and greenhouse gas monitoring.
Fire resistance relies on the dominance of E. minus, whose negatively geotropic, water-absorbing roots form a dense, spongy mat that insulates underlying peat and sheltering fauna from combustion. The peat itself is largely composed of highly decomposition-resistant Empodisma roots and stems. Although fire burns almost all surface vegetation, Empodisma resprouts rapidly, overgrowing burnt material and incorporating it as recalcitrant carbon into accreting peat. Multiple charcoal horizons in cores up to 8 metres deep confirm fire has been a persistent feature for millennia, being more frequent prior to European colonisation. Crucially, without regular burning, competing woody plants suppress Empodisma, reducing peat deposition and increasing vulnerability to catastrophic combustion through desiccation of the exposed peat.
Despite — or because of — recurring fire, these peatswamps store between 300 and 3,551 Mg C ha⁻¹, with deeper peats comparable to tropical peat swamp forests and far exceeding temperate peatlands. Temperate Australian Empodisma peatlands are shallower and severely damaged by wildfire, suggesting the warm, wet subtropical climate is critical to fire resilience and peat accretion.
Managed burns emulating Indigenous cultural burning practices are now incorporated into National Parks management and appear key to maintaining peatland integrity under increasingly fire-prone climates. Where drainage or drought dries the peat, ignition risk escalates and peat may smoulder for months. Protecting the water table is fundamental to peatland protection.