A comparative study of ancient sedimentary DNA, pollen and macrofossils from permafrost sediments of northern Siberia reveals long-term vegetational stability

Although ancient DNA from sediments (sedaDNA) has been used to investigate past ecosystems, the approach has never been directly compared to the traditional methods of pollen and macrofossil analysis. We conducted a comparative survey of 18 ancient permafrost samples spanning the Late Pleistocene (46–12.5 thousand years ago), from the Taymyr Peninsula in northern Siberia. The results show that pollen, macrofossils and sedaDNA are complementary rather than overlapping, and in combination reveal more detailed information on plant palaeocommunities than can be achieved by each individual approach. SedaDNA and macrofossils share greater overlap in plant identifications than with pollen, suggesting that sedaDNA is local in origin. These two proxies also permit identification to lower taxonomic levels than pollen, enabling investigation of temporal changes in species composition and the determination of indicator species to describe environmental changes. Combining data from all three proxies...尽管沉积物来源的古DNA（sedaDNA）已被用于探究古生态系统，但该方法从未与传统的孢粉与大化石分析方法进行过直接对比。本研究针对西伯利亚北部泰梅尔半岛采集的18份更新世晚期（距今4.6万至1.25万年）永久冻土古样品开展了对比调查。研究结果表明，孢粉、大化石与沉积物古DNA三者并非相互重叠，而是互为补充；三者联用可获取比单一方法更为详尽的古植物群落相关信息。相较于孢粉，沉积物古DNA与大化石在植物鉴定结果上的重合度更高，这表明沉积物古DNA的来源具有地域性。相较于孢粉，这两类代用指标还可实现更低分类学层级的物种鉴定，从而能够开展物种组成的时间变化研究，并确定用以指示环境变化的指示物种。整合三类代用指标的数据……