Seven of the most prevalent forest tree species in Europe have demonstrated their ability to preserve genetic diversity, even amid significant environmental changes. This resilience is noteworthy, especially considering that their ranges have decreased and their populations have drastically reduced during the cycles of ice ages.
Recent research indicates that seven of the most prevalent forest tree species in Europe have the ability to maintain their genetic diversity despite significant environmental shifts. This resilience is particularly remarkable given the reduction in their geographical ranges and sharp declines in tree populations during ice age cycles. These findings come from a study conducted by a consortium that includes Uppsala University and was published in Nature Communications.
“From a biodiversity standpoint, these findings are encouraging because these trees are essential species that many other organisms rely upon,” remarks Pascal Milesi, an Associate Professor of Plant Ecology and Evolution at Uppsala University and the lead author of the study.
The goal of the researchers was to explore how the ice age cycles affected the genetic diversity of tree species. Trees have endured through both warm and cold climates. Approximately 10,000 years ago, the last ice age significantly constricted the range of these trees. Scientists initially assumed this would lead to low genetic diversity. However, the study revealed the opposite — the trees possessed high genetic diversity, allowing them to adapt well to the severe changes in their environments.
“We think that this substantial genetic diversity stems from how these tree species managed to survive the ice ages, coupled with the fact that tree pollen can travel great distances, often thousands of kilometers, linking widely separated trees. This is a hopeful sign. The evolutionary mechanisms established in the past may assist in tackling today’s rapid climate change,” states Milesi.
Alongside scientists from 22 different European research institutions, the study focused on seven common European forest tree species, gathering samples from around 3,500 trees across 164 separate populations in Europe. Their DNA was subsequently extracted and analyzed.
“In contrast to previous beliefs, the ice age cycles had minimal influence on the genetic diversity of these seven crucial species. This is primarily due to a set of unique features, such as their long life cycles and the capability of their pollen to disperse over vast distances,” explains Milesi.
In Sweden, the research particularly examined Norway spruce, Scots pine, and silver birch, which predominantly constitute the country’s forests and are vital for various other species. These trees also represent the majority of timber production in Swedish forestry, highlighting their economic and societal importance.
“In light of the ongoing sixth mass extinction and the current biodiversity crisis, it is easy for people to feel hopeless and consider giving up. However, this study provides an encouraging message regarding our forests and offers crucial insights for managing forest biodiversity in the context of climate change,” concludes Milesi.
The species involved in this study are: 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).
