European droughts hit British trees the hardest

"As our climate continues to warm, droughts will become more frequent and more extreme," said plant ecologist Alistair Jump.

By Brooks Hays

A stand of beech trees in South Wales, where researchers say the effects of drought are already readily apparent. Photo by Alistair Jump/University of Stirling

Beech trees in the forests of southern England are less resistant to drought than those growing elsewhere in Europe. Scientists determined as much after analyzing tree ring data from across Western Europe.

The results of the beech tree study, funded by the Natural Environment Research Council, were published this week in the journal Global Change Biology.

"Beech trees across Europe are extremely vulnerable to the effects of drought," lead study author Alistair Jump, a professor of plant ecology at the University of Stirling, said in a news release. "These long dry spells cause sudden and widespread reduced growth within the species."

"We might expect beech forests in hotter and drier regions of Europe, such as southern France and Spain, to be most at risk," Jump continued. "However, we have found that the south of the U.K. -- the very center of the area where the species grows -- is most badly affected."

The tree ring data also revealed the long-lasting effects droughts can have on trees. Many of the beech trees that survived the severe drought and record heat of the summer of 1967 continue to show reduced growth 40 years later.

Researchers suggest the effects of global warming will be equally long-lasting and severe -- if not worse.

"As our climate continues to warm, droughts will become more frequent and more extreme," said Jump. "Beech forests across Europe will be hit increasingly hard, with a high risk of widespread mortality when the next big dry spell hits -- particularly in southern parts of the U.K."

"We know the effects of the 1967 drought have lasted to the present day and expect that future changes to our forests may be sudden and put many of our most iconic beech woods at significant risk," Jump concluded.