Data from: Lake sediment multi-taxon DNA from North Greenland records early post-glacial appearance of vascular plants and accurately tracks environmental changes

High Arctic environments are particularly sensitive to climate changes, but retrieval of paleoecological data is challenging due to low productivity and biomass. At the same time, Arctic soils and sediments have proven exceptional for long-term DNA preservation due to their constantly low temperatures. Lake sediments contain DNA paleorecords of the surrounding ecosystems and can be used to retrieve a variety of organismal groups from a single sample. In this study, we analyzed vascular plant, bryophyte, algal (in particular diatom) and copepod DNA retrieved from a sediment core spanning the Holocene, taken from Bliss Lake on the northernmost coast of Greenland. A previous multi-proxy study including microscopic diatom analyses showed that this lake experienced changes between marine and lacustrine conditions. We inferred the same environmental changes from algal DNA preserved in the sediment core. Our DNA record was stratigraphically coherent, with no indication of leaching between layers, and our cross-taxon comparisons were in accordance with previously inferred local ecosystem changes. Authentic ancient plant DNA was retrieved from nearly all layers, both from the marine and the limnic phases, and distinct temporal changes in plant presence were recovered. The plant DNA was mostly in agreement with expected vegetation history, but very early occurrences of vascular plants, including the woody Empetrum nigrum, document terrestrial vegetation very shortly after glacial retreat. Our study shows that multi-taxon metabarcoding of sedimentary ancient DNA from lake cores is a valuable tool both for terrestrial and aquatic paleoecology, even in low-productivity ecosystems such as the High Arctic.

高北极（High Arctic）环境对气候变化尤为敏感，但受限于极低的生产力与生物量，古生态数据（paleoecological data）的获取颇具挑战。与此同时，北极地区的土壤与沉积物因常年维持低温，已被证实可实现DNA的长期保存。湖泊沉积物留存着周边生态系统的DNA古记录（DNA paleorecords），仅需单一样本即可获取多种生物类群的遗传信息。本研究对取自格陵兰最北端海岸布利斯湖（Bliss Lake）的全新世（Holocene）沉积物岩芯中提取的维管植物、苔藓植物（bryophyte）、藻类（尤其硅藻（diatom））以及桡足类（copepod）的DNA进行了分析。此前一项包含硅藻显微分析的多代用指标研究显示，该湖泊曾经历海洋与淡水湖泊环境的交替变迁。本研究通过沉积物岩芯中留存的藻类DNA，推导出了相同的环境变迁过程。本研究得到的DNA记录在地层上具有一致性，未出现层间淋溶的迹象；跨类群比对结果也与此前推断的当地生态系统变迁相符。研究从几乎所有地层（包括海洋与淡水湖泊沉积阶段）中均提取到了可靠的古代植物DNA，并获取了植物群落存在情况的显著时间演化特征。植物DNA的分布结果与预期的植被历史大体吻合，但包括木本植物黑果岩高兰（Empetrum nigrum）在内的维管植物的极早期出现记录，证实了冰川消退后不久该区域便已存在陆地植被。本研究证实，对湖泊岩芯沉积物古DNA进行多类群元条形码（metabarcoding）分析，是适用于陆地与水生古生态学研究的有效手段，即便在高北极这类生产力极低的生态系统中亦是如此。