Tree death observed after summer of 2018

A sign saying 'Fire ban - danger of forest fire' in central Switzerland in July 2018 Keystone

After the very hot and dry summer of 2018, Swiss researchers conducted 13 studies on the consequences of the extreme weather on forests and the water cycle. The conclusion of the first results is that while forests are not dying, trees are. 

In many parts of Switzerland, the summer of 2018 was the longest and hottest period without precipitation since systematic weather records began in 1864, the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) said in a statementExternal link on Thursday. 

The institute has not only been monitoring the development of forests nationwide for 134 years, but also has extensive experience of hydrology and biodiversity. 

The first results of six of its 13 analyses are now available. It was found that premature leaf discolouration in beech trees led to losses in wood growth, that forest fires caused by lightning were more frequent than usual and that such a serious water shortage occurs on average every 100 years. 

“The drought and heat in 2018 were extraordinary and the consequences for the forest are becoming increasingly visible: in many places trees are weakening, tree growth is reduced, canopy parts or entire trees are dying,” concluded Andreas Rigling, head of the Forest Dynamics Research Unit at WSL. 

“Even if we do not speak of forest dieback, important forest services will be affected locally.”