The spectacular results have emerged, in part, by studying the DNA of modern spruce - which clearly portray two Scandinavian types - and also by analysing the composition of pine and spruce DNA in sediments from lake-core samples. Additionally, researchers analysed other ancient DNA and the remains of macrofossils to reach their conclusions.
Two locations in Norway have proved particularly lucrative for the researchers. One of them, Andya Island, in north-western Norway, is the source of material dated between 17,700 and 22,000 years-old. During the last ice age, the island was an ice-free pocket, one "refuges" on the edge of the enormous ice sheet, which blanketed at that time nearly all of Scandinavia.
"The other evidence, which supports the surviving conifers in the midst of an ice age, originates in Trndelag, central Norway. One hypothesis is that trees were able to survive on the top of nunataks, the exposed ridges or peaks of mountains protruding from glacial cover, or in more sheltered areas close to the coast where proximity to the temperate conditions of the Atlantic Ocean favoured survival. These areas must have provided sites for roots to anchor and trees to grow in the challenging climate," says Laura Parducci, University of Uppsala.
Today, nunataks can be found protruding from the Greenlandic ice sheet, though without any trees to adorn them.
Money in trees
According to Inger Greve Alsos, Troms University Museum, their results are not just useful within the context of revising the history of Scandinavian conifers.
"The essence of our studies is that they challenge conventional scientific notions of the spreading of trees, biodiversity and survival in harsh environments from a global perspective; especially with regards to climate change or other changes and interventions in nature. I also believe that our results will have economic significance. We now know that there are two types of natur
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| Contact: Professor Eske Willerslev ewillerslev@snm.ku.dk (45) 28-75-13-09 University of Copenhagen Source:Eurekalert |