Beech trees in southern Europe are facing drastic growth declines

Researchers at Johannes Gutenberg University Mainz (JGU) have collaborated with 32 scientific organizations to analyze the effect of climate change on Fagus sylvatica, a type of beech tree found in Europe. They discovered that these magnificent trees are threatened by climate change, especially in southern Europe.   

“Beech is one of the most important forest species in Europe from an ecological and socio-economical perspective,” wrote the study authors. “Beech played a dominant role in postglacial reforestation, rapidly spreading from its Mediterranean refuges to the central and northern regions of the continent.” 

“Currently, in the face of rapid climate change, beech may be endangered in its geographical and ecological range. However, the species’ resilience to predicted changes and its ecological plasticity across the distribution range are not well understood.”

The scientists gathered 780,000 ring measurements on 5,800 beech trees at 324 sites across Europe, from the north of Scotland to mainland Greece to carry out the analysis. Not only were the researchers able to extrapolate past growth rates, but they were also able to predict future growth by looking at the growth record for the past 60 years. 

By comparing two 31-year periods, 1955 to 1985 and 1986 to 2016, the experts determined that as time passed, beech tree growth had declined in almost all regions studied. In southern Europe, beech tree growth had been reduced by 20 percent.  

Based on this information, study lead author Dr. Edurne Martinez del Castillo predicts that over the next 70 years, we will continue to see a considerable decrease in beech tree growth. 

“We expect high productivity declines due to increased drought severity, especially at the southern limits of the beech’s distribution range,” said Martinez del Castillo.

“Even assuming a relatively optimistic climate change scenario, we will see sharp growth reductions of up to 30 percent in southern Europe between 2020 and 2050 compared to the 1986 to 2016 period.”

Climate scientists base those numbers on an increase in warming of one-degree Celsius. However, a pessimistic model that expects a five-degree warming predicts a more significant loss in production. “In southern Europe, losses could even exceed 50 percent,” said Martinez del Castillo.

Even in northern, mountainous areas such as Sweden and Norway, where climate change could boost beech growth, this growth will not counter the losses sustained in the rest of Europe.  

Moreover, this situation could cause a positive feedback loop because beech forests serve as carbon sinks. Fewer and smaller beech trees will lead to less carbon taken up by the trees and more in the air. 

The researchers suggest that we implement forest adaptation efforts to avoid detrimental environmental and economic impacts. 

The study is published in the journal Communications Biology.

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By Erin Moody , Earth.com Staff Writer