Written by John-Inge Svendsen, professor at the Bjerknes Centre and the Department of Earth Science at the University of Bergen
We have discovered a lake in the Polar Ural Mountains in Arctic Russia that contains extremely thick layers of sediments, from which we obtained a 24 m long core that covers the last 24 000 years (Svendsen et al., 2019). Here we report DNA analysis of the sediments, which reveal a changing, but surprisingly species-rich flora that has endured through dramatic climatic shifts for 24,000 years ago (Clarke et al., 2019).
A total of 162 different plant species were found. Despite the fact that there have been some major changes in vegetation over this long period, many species have survived in this mountainous area right up to our days. Thus, they must have adapted to the environmental changes, probably because they have moved up and down the mountain sides as the climate changed. The findings are presented in greater detail on this UiT web site.
This is among the very best DNA profiles obtained from sedimentary records anywhere on Earth. The good preservation of DNA is probably due to the cold climate and the high clay content in the sediments, small flaky particles that the DNA molecules adhere to.
To our surprise, the DNA analyses also revealed the presence of several species of earth worms, even during the coldest peak of the last Ice Age (Lammers et al., 2019). Before this discovery was made, it was unknown that these earth worms have survived in this area with deep permafrost and extremely cold winters.
The results have been produced in the interdisciplinary project Climate History Along the Arctic Seaboard of Eurasia (CHASE) led by John Inge Svendsen, Department of Earth Science, University of Bergen and the Bjerknes Center for Climate Research.
The DNA analysis was performed by a research team led by Inger Alsos at the University of Tromsø. The results from the plant DNA analysis were recently published in the journal Nature Scientific Reports whereas the animal DNA and several other results from the lake core were published in a special issue of the journal Boreas.
References
- Clarke, C.L., Edwards, M.E., Gielly, L., Ehrich, D., Hughes, P.D.M., Morozova, L.M., Haflidason, H., Mangerud, J., Svendsen, J.I., Alsos, I.G., 2019. Persistence of arctic-alpine flora during 24,000 years of environmental change in the Polar Urals. Nature Scientific Reports 9, 19613.
- Lammers, Y., Clarke, C.L., Erséus, C., Brown, A.G., Edwards, M.E., Gielly, L., Haflidason, H., Mangerud, J., Rota, E., Svendsen, J.I., Alsos, I.G., 2019. Clitellate worms (Annelida) in lateglacial and Holocene sedimentary DNA records from the Polar Urals and northern Norway. Boreas 48, 317-329.
- Svendsen, J.I., Færseth, L.M.B., Gyllencreutz, R., Haflidason, H., Henriksen, M., Hovland, M.N., Lohne, Ø.S., Mangerud, J., Nazarov, D., Regnéll, C., Schaefer, J.M., 2019. Glacial and environmental changes over the last 60 000 years in the Polar Ural Mountains, Arctic Russia, inferred from a high-resolution lake record and other observations from adjacent areas. Boreas 48, 407-431