Ancient plant DNA reveals High Arctic greening during the Last Interglacial

Summer warming is driving a greening trend across the Arctic, with the potential for large-scale amplification of climate change due to vegetation-related feedbacks (Pearson et al., 2013). Because observational records are sparse and temporally limited, past episodes of Arctic warming can help elucidate the magnitude of vegetation response to temperature change. The Last Interglacial (LIG; 129,000–116,000 years ago) was the most recent episode of Arctic warming on par with predicted 21st century temperature change (Otto-Bliesner et al., 2013; Post et al., 2019). However, high-latitude terrestrial records from this period are rare, so LIG vegetation distributions are incompletely known. Pollen-based vegetation reconstructions can be biased by long-distance pollen transport, further obscuring the paleoenvironmental record. Here, we present the first LIG vegetation record based on ancient DNA in lake sediment and compare it with fossil pollen. Comprehensive plant community reconstructions ...