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., Nat. Clim. Chang. (3), 673–677 (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 to 116,000 y ago) was the most recent episode of Arctic warming on par with predicted 21st century temperature change [Otto-Bliesner et al., Philos. Trans. A Math. Phys. Eng. Sci. (371), 20130097 (2013) and Post et al., Sci. Adv. (5), eaaw9883 (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 a LIG vegetation record based on ancient DNA in lake sediment and compare it with fossil pollen. Comprehensive plant community reconstructions through the last and current interglacial (the Holocene) on Baffin Island, Arctic Canada, reveal coherent climate-driven community shifts across both interglacials. Peak LIG warmth featured a ∼400-km northward range shift of dwarf birch, a key woody shrub that is again expanding northward. Greening of the High Arctic—documented here by multiple proxies—likely represented a strong positive feedback on high-latitude LIG warming. Authenticated ancient DNA from this lake sediment also extends the useful preservation window for the technique and highlights the utility of combining traditional and molecular approaches for gleaning paleoenvironmental insights to better anticipate a warmer future. © 2021 National Academy of Sciences. All rights reserved.
|Original language||English (US)|
|Number of pages||9|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Mar 30 2021|
Bibliographical noteFunding Information:
ACKNOWLEDGMENTS. We gratefully acknowledge the Qikiqtaani Inuit and government of Nunavut for access to their land (Nunavut Research Institute Permits #0102217R-M and #0203819R-M). We thank CH2MHill Polar Services, Polar Continental Shelf Program, Joshua Akavak, Lasalie Joanasie, Zach Montes, and Devon Gorbey for field support and Mahsa Mousavi Mousavi-derazmahalleh and Katrina West for bioinformatics expertise. We thank the INSTAAR Laboratory for AMS Radiocarbon Preparation and Analysis for sample preparation and insights. This research was funded by the US NSF (Office of Polar Programs Awards #1737712 to G.H.M. and J.S., #1737716 to E.K.T., and #1737750 to M.K.R.; NSF Graduate Research Fellowship Program Award #1144083 to S.E.C.; and NSF Doctoral Dissertation Research Improvement Award #1657743 to G.H.M. and S.E.C.), National Geographic Society, CU Center for the Study of Origins, CU Graduate School, and the Geological Society of America.
© 2021 National Academy of Sciences. All rights reserved.
- Arctic greening
- Last Interglacial
- Sedimentary ancient DNA
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.