European Palaeobotany and Palynology Conference 2026

Forests, since their emergence in the Middle Devonian (c. 400 Ma), have profoundly transformed terrestrial vegetation, climate, and environment. A number of fossil forests from geologic ages have been reported around the globe and studied in light of palaeobotanical systematics, taxonomy and plant composition, yet forest communities and ecosystems remain poorly understood. Here, we compile a global dataset of in situ fossil forests and quantitatively assess the evolution of fossil forest communities using multiple ecological parameters and analytical approaches, focusing on forest composition, canopy height, tree density, biomass, stand structure, and spatial pattern. We show that: (1) canopy height increased twice as the first during the Late Devonian–Early Carboniferous and the second the Middle Triassic–Late Jurassic; (2) biomass peaked in the Middle Devonian–Late Carboniferous lycopsid forests and stabilized at levels comparable to extant forests after the Middle Triassic; (3) tree density reached the highest in Devonian–Carboniferous forests, especially lycopsid-dominated communities, but declined to values similar to modern forests following gymnosperm dominance in the Middle Triassic; and (4) spatial patterns remained predominantly aggregated throughout forest evolution, resembling those of extant forests. Four evolutionary stages are recognized as Initial Forest (Eifelian–Frasnian), Geocarbon Forest (late Famennian–early Permian), Dawn Forest (middle Permian–Early Triassic), and Preset Forest (Middle Triassic–Late Cretaceous). These quantitative assessments reveal long-term changes in fossil forest communities and bridge the gap between fossil and modern forest ecosystems.