An 8.6 million year reconstruction of paleotemperatures and paleovegetation from Lake Baikal, Russia, derived from Baikal Drilling Project core materials. This dataset also includes compiled paleovegetation data from the Late Pliocene and Early Pleistocene from boreal regions and a new global mean surface temperature stack derived from published sea surface temperature records. Paleotemperatures were estimated from the methylation of branched glycerol dialkyl glycerol tetraethers. Paleovegetation was reconstructed from plant wax n-alkane distributions and published pollen data. Paleovegetation data were compiled from published studies.

Methods: We reanalyzed published pollen spectra (n = 993) from the Lake Baikal drill cores (Maki et al. 2003; Hase et al. 2002; Kawamuro et al. 2000) using the methods of Prentice et al. (1996) to identify the most likely dominant biome represented by each sample.All pollen grains were counted by the same analytical team (Maki et al. 2003; Hase et al. 2002; Kawamuro et al. 2000). Pollen spectra with fewer than 90 grains were excluded from consideration, leaving 841 spectra. The original pollen counts are archived electronically by the Lake Biwa Museum. Each pollen taxon was assigned to a plant functional type (PFT) based on the biology of the plant species as in the methodology of Prentice et al. (1996). Some taxa were assigned to more than one PFT because they either contain several species with different biological characteristics or different growth habits depending on their environment (Prentice et al. 1996).  Likewise, some plant functional types are assigned to more than one biome (Prentice et al. 1996). Each pollen sample was assigned affinity scores by the following formula. Aik = Σδi√(max[0, pjk -θj]) Aik is the affinity of a given pollen sample k for biome i; δij is the entry in the biome-taxon matrix for biome i and taxon j; pjk are the pollen taxon percentages counted in the sample, and θj is a universal threshold pollen percentage of 0.5% to minimize the influence of single pollen grains on PFT affinity scores.Pollen samples were then assigned to the biome with the highest sum of affinity scores.Taxa were assigned to plant functional types and biomes based on the published matrices used in regional studies (see Tarasov et al. 2011; Takahara et al. 2010; Takahara et al 2000; Gotanda et al. 2002; Prokopenko et al. 2010; Brigham-Grette et al. 2013). Further funding information: PR 1414/1-1 Deutsche Forchungsgemeinshaft Priority Program "ICDP" 1006 Geological Society of America Continental Drilling Science Division Graduate Student Grant 13282-21* Sigma Xi Grants in Aid of Research G20211001-101