Leaf flammbility and volatiles of Ginkgo, Agathis, and Dicksonia

The Triassic-Jurassic Boundary marks the third largest mass extinction event in the Phanerozoic, characterised by a rise in CO2-concentrations from ~600 ppm to ~2100 – 2400ppm, coupled with a ~3.0 – 4.0°C temperature rise. This is hypothesized to have induced major floral turnover, altering vegetation structure, composition and leaf morphology, which in turn are hypothesized to have driven changes in wildfire. However, the effects of elevated CO2 on fuel properties, such as chemical composition of leaves, are also important in influencing fire behaviour, but yet have not been considered.
We test this by selecting three Triassic analogue species grown experimentally in different atmospheric compositions, and analyse variations in leaf chemistry, and leaf level flammability. These data were used to inform a fire behaviour model.
We find that all three species tested showed a reduction in their volatile component, leading to lower flammability. Accounting for these variations in a model, o...