Spruce trees' reconquest of Sweden after the last Ice Age took 10,000 years

It took more than 10 millennia from when the first spruces returned to Sweden after the last Ice Age until the species became widespread, according to a new study. The researchers were surprised by the slow rate of initial dispersal.

The Norway spruce was common before the last Ice Age.

The accounts of its migration have been based on the ancient lake deposits. The studies led to the conclusion that spruce migrated from the northeast to southern Sweden as late as 1000 years ago. Researchers have found that it took a long time for the spruce to return to its former dominance.

The scientists analyzed ancient DNA in the new study, which was published in the journal Nature Communications. The south of Sweden has been shown to have been home to spruce 7,000 years ago, far earlier than previous studies have shown.

Although it was one of the first trees to be re-established, it failed to colonize the region. Kevin Nota, the first author of the study, says that this is surprising since pioneer plant species are usually at an advantage.

It's not clear what has held the spruce back over the past ten thousand years. A new study shows that the first trees in place were related to the solitary clonal spruces that are found high up on Sweden's mountainsides today. New trees have regenerated from the tree's surviving root system when the trunk has died. Some have been reproduced by root suckers.

According to the new study, the first spruces probably survived the last Ice Age in small densities close to the eastern and possibly at the southern margin of the Scandinavian Ice Sheet, rather than at the western edge. The provenance of the spruces that migrated from the northwest was similar to the ones that arrived first.

Laura Parducci is the principal investigator of the study and she says that the Swedish spruce seems to have lived through several earlier attempts to take over the forests of Scandinavia.

More information: Kevin Nota et al, Norway spruce postglacial recolonization of Fennoscandia, Nature Communications (2022). DOI: 10.1038/s41467-022-28976-4 Journal information: Nature Communications Citation: Spruce trees' reconquest of Sweden after the last Ice Age took 10,000 years (2022, April 11) retrieved 11 April 2022 from https://phys.org/news/2022-04-spruce-trees-reconquest-sweden-ice.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.