Evrim Yazgin
Cosmos science journalist
In some positive news, a big and broad study has found that 7 of Europe’s most common forest trees have adapted to major climatic shifts and protected their genetic diversity.
The trees, the researchers found, were able to do this despite sharp declines in population range and numbers, especially during ice ages. The results of the study are published in Nature Communications.
“From a biodiversity perspective, this is very positive because these trees are keystone species on which many other species depend,” says first author Pascal Milesi, from Uppsala University in Sweden.
Forests cover about 38% of land area in Europe today. This has fallen from about 65% roughly 6,000 years ago.
During the last Ice Age about 10,000 years ago, too, forest cover was greatly decreased. Scientists thought this would be accompanied by an associated drop in genetic diversity. But the new study found the opposite.
In fact, the species which were able to maintain high genetic diversity were more resilient to drastic habitat changes.
“This is a welcome sign,” Milesi says. “The evolutionary processes that were at play in the past may also be useful to cope with today’s rapid climate change.”
Milesi and researchers from 22 European research institutions collected needles and leaves from 3,500 trees from 164 populations across the continent for DNA analysis.
They focused on 7 key species: Fagus sylvatica (European beech), Pinus pinaster (Maritime pine), Quercus petraea (Sessile oak), Betula pendula (Silver birch), Pinus sylvestris (Scots pine), Picea abies (Norway spruce) and Populus nigra (Black poplar).
“Contrary to what was long thought, the ice age cycles had little impact on the genetic diversity of these 7 key species. This is mainly explained by a combination of unique characteristics, namely long generation time and the ability of their pollen to spread thousands of kilometres,” says Milesi.
“Due to the sixth mass extinction event and the ongoing biodiversity crisis, people can easily get the feeling that it is too late and be ready to give up. This study sends a positive signal about our forest and provides important information to help manage forest biodiversity in the face of climate change,” Milesi adds.
Not all organisms have the same track record with drastic climate change, though. Scientists continue to stress that more will be lost and ecosystems irreparably damaged without urgent action.
