Ancient plant DNA reveals High Arctic greening during the Last Interglacial
Ancient plant DNA reveals High Arctic greening during the Last Interglacial
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DOI：
10.1073/pnas.2019069118
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发表时间：
2021-03-30
影响因子：
11.1
通讯作者：
Miller, Gifford H.
中科院分区：
文献类型：
--
作者：
Crump, Sarah E.;Frechette, Bianca;Miller, Gifford H.
夏季变暖正在推动整个北极的绿化趋势，由于与植被相关的反馈，气候变化有可能大规模放大[Pearson等人，NAT。克里姆。张先生。(3)，673-677(2013)]。由于观测记录稀少且时间有限，过去北极变暖的事件可以帮助阐明植被对温度变化的反应程度。最后一次间冰期([LIG]，距今12.9万至11.6万年前)是北极变暖的最新时期，与预测的21世纪气温变化相当[Otto-Bliesner等人，Philos]。翻译过来的。一门数学。太棒了。英语。SCI。(20130097)和波斯特等人，《科学》。Adv.(5)，eaaw9883(2019)]。然而，这一时期的高纬度陆地记录很少，所以LIG植被的分布还不完全清楚。以花粉为基础的植被重建可能会受到远距离花粉运输的影响，进一步模糊了古环境记录。在这里，我们介绍了基于湖泊沉积物中古代DNA的LIG植被记录，并将其与化石花粉进行了比较。通过加拿大北极巴芬岛上一次和当前间冰期(全新世)的全面植物群落重建，揭示了两个间冰期之间一致的气候驱动的群落变化。Peak LIG温暖的特征类似于矮桦向北移动400公里，矮桦是一种关键的木质灌木，再次向北扩展。高北极地区的绿化--在这里由多个代理人记录--可能代表着对高纬度LIG变暖的强烈积极反馈。从这个湖泊沉积物中鉴定出的古代DNA也延长了这项技术的有用保存窗口，并突显了将传统和分子方法结合起来收集古环境洞察以更好地预测更温暖的未来的效用。
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 similar to 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.