Drought significantly increased damaged forest areas in central Germany – report

More than half of the forest in some central German regions is "severely damaged" following extreme drought periods over the past years, according to a report by the Helmholtz Centre for Environmental Research (UFZ). Fifty-two percent of the overall forest and 76 percent of the conifers in the Harz region were severely damaged in 2022, UFZ said following a novel analysis of high-resolution satellite data. As recently as 2017, only nine percent of the forest and eight percent of conifers showed severe damages, the researchers said. "Heat, drought and insects, as well as their interaction, negatively affect the forest and result in subsequent damage such as windfall and elevated risk of fire," explained UFZ researcher Anne Reichmuth.

Roughly one third of Germany is covered by forest. The UFZ analysis revealed forests in Thuringia, Sauerland, and Saxon Switzerland had also suffered a substantial increase in damages. The researchers said forests of the central German upland regions in which spruce was planted after 1945 were particularly affected, but they also noted significant regional losses among pines, beech and oak trees. Deciduous trees are especially affected by so-called complex diseases that weaken their immune system and their defensive strength, UFZ said. But the institute also found forested regions in Germany which did not deteriorate substantially between 2016 and 2022, such as the Black Forest and the Erzgebirge (Ore mountains). “The silver fir, which is common in the Black Forest, is better adapted to climate change than the Norway spruce,” the researchers said.

Forests act as natural carbon sinks, playing an important role in achieving climate targets by balancing out emissions that are hard to avoid. The German climate law already prescribes annual net-negative emissions targets for the land use sector (LULUCF, which also includes other carbon sinks and sources, for example peatland) for 2030, 2040 and 2045, and the government is currently working on a long-term strategy for negative emissions. One goal of the strategy is to strengthen natural carbon sinks, including forests.