Forest

In ten percent of forests in central Europe, trees lost some or all of their leaves too early in the dry summer of 2018. This is shown by calculations and satellite image analyses of the Swiss Federal Institute for Forest, Snow and Landscape Research WSL. Central and eastern Germany along with the Czech Republic were the most severely affected. Since it was less hot and dry in the mountains, Swiss forests suffered less damage.

Until now, science has assumed that the amount of carbon formed in needles is the sole driving force for wood growth in coniferous trees. An international research team led by the Swiss Federal Research Institute WSL has now discovered in the Lötschental (Canton Valais) that the level of water pressure in the trunk is also a decisive factor for growth.

With climate change, summers in Switzerland will become hotter and drier, like those of 2003 and 2018. A research team led by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) has for the first time mapped the stress behaviour of beech trees in increasingly dry conditions. In soils that can store only small amounts of water and dry out quickly, beeches will be more likely to desiccate as the climate changes.