We compiled published palaeobotanical data from 25 localities in West and East Siberia, the Russian Far East, northern Kazakhstan, Mongolia, and northwestern China. Of the 25 sites, 24 were either not included or published more recently than the PRISM3/4 biome reconstruction ​(Salzmann et al., 2008, doi:10.1111/j.1466-8238.2008.00381.x)​. These additional data substantially improve the data coverage in northern Eurasia and permit a more rigorous assessment of the vegetation boundary conditions used in the PlioMIP experiments.Compiled vegetation data from Siberia classified into the standard biomes of the PRISM4 Pliocene vegetation reconstruction. All data come from published studies, many of which were published in Russian language journals.

Originally published biome / vegetation classifications were adapted to the PRISM4 framework as follows:Grassland: SteppeOpen Woodland / Savannah: Lesosteppe (Forest-Steppe), Steppe-Forest, Open WoodlandTemperate Forest: Broadleaf Deciduous Forest, Deciduous Forest, Temperate ForestBoreal Forest: Taiga, Boreal Taiga, Listvenista (Latch Forest), Pine Forest, Spruce Forest, Conifer Forest, Boreal ForestTundra: Tundra, Forest-Tundra, Shrub Tundra