Islands in the ice: detecting past vegetation on Greenlandic nunataks using historical records and sedimentary ancient DNA meta-barcoding

Nunataks are isolated bedrocks protruding through ice sheets. They vary in age, but represent island environments in “oceans” of ice through which organism dispersals and replacements can be studied over time. The J.A.D. Jensen’s Nunataks at the southern Greenland ice sheet are the most isolated nunataks on the northern hemisphere - some 30 km from the nearest biological source. They constitute around 2 km2 of ice-free land that was established in the early Holocene. We have investigated the changes in plant composition at these nunataks using both the results of surveys of the flora over the last 130 years, and through reconstruction of the vegetation from the end of the Holocene Thermal Maximum (5528±75 cal yr BP) using meta-barcoding of plant DNA recovered from the nunatak sediments (sedaDNA). Our results show that several of the plant species detected with sedaDNA are described from earlier vegetation surveys on the nunataks (in 1878, 1967 and 2009). In 1967, a much higher biodivers...

冰原岛峰（Nunataks）是从冰盖中突出的孤立基岩。其形成年代各异，但代表了冰“洋”中的岛屿环境，通过这些环境可长期研究生物的扩散与更替。格陵兰冰盖南部的J.A.D. Jensen冰原岛峰是北半球最孤立的冰原岛峰，距离最近的生物源地约30公里。它们构成了约2平方公里的无冰陆地，形成于全新世早期。我们通过两种方法研究了这些冰原岛峰的植物组成变化：一是过去130年的植物区系调查结果，二是利用从冰原岛峰沉积物中提取的植物DNA宏条形码技术（meta-barcoding），重建全新世大暖期（Holocene Thermal Maximum）末期（5528±75 校准年 BP）的植被。研究结果显示，沉积物DNA（sedaDNA）检测到的部分植物物种，在早期（1878年、1967年和2009年）的冰原岛峰植被调查中已有记录。1967年，生物多样性显著更高……