Plant DNA metabarcoding data from a sediment core from Emu Co, eastern Tibetan Plateau

Here, we provide the raw plant DNA metabarcoding data archived in the Emu Co lake sediment core (33.2311°N, 100.9889°E; 4020 m a.s.l.), spanning the Holocene period (12.6 cal ka BP to present). We extracted sediment ancient DNA using the DNeasy PowerSoil DNA Isolation Kit (Qiagen, Germany), with 250 mg of input material. Each sample underwent two extractions, using a total sediment volume of 500 mg, to obtain enough DNA for polymerase chain reaction (PCR) amplification. For PCR amplification, we employed plant universal primers g and h, targeting a short region of the trnL intron in the chloroplast genome (Taberlet et al., 2007). To facilitate demultiplexing of samples after sequencing, we modified the forward and reverse primers with a NNN-8 bp tag at the 5' end (Coissac et al., 2012; De Barba et al., 2014). Each batch of PCR included a 'No template control' (NTC) containing only the PCR chemical and the extraction blank control corresponding to the analysed sample batch. Library preparation followed the MetaFast library protocol and amplicon sequencing was conducted on an Illumina NextSeq device using 2x150 bp paired-end sequencing, performed by Fasteris SA, Switzerland.