Every ten years, people in green clothing with laptops and tape measures populate the German forest. It is then measured thoroughly. How big are the trees, how old, how healthy? Which trees are there and how are they doing? Which ones are no longer standing? The data, compiled by foresters from the federal states, then flows into the “Federal Forest Inventory”. It has been available since Tuesday and is a cause for concern.
Because what has caused problems for the forest in recent years – forest fires, drought, pest plagues – can be found there in black and white, measured in cubic meters, dead wood and carbon dioxide. The forests should store the latter in particular diligently; after all, they keep up with growth. But the extreme heat of 2018 to 2020 reversed this: instead of absorbing and binding a little more carbon dioxide year after year, they released it – for example by causing dead wood to decompose into humus and thereby release the climate-damaging gas. The amount of greenhouse gases created in this way would have to be bound again in new greenery – but the above-ground mass (green in the graphic) shrank.
“The forest is failing as a climate protector.”
The carbon stock in German forests has fallen by 41.5 million tons since 2017 alone. For comparison: the entire agricultural sector causes 60 million tons of greenhouse gas emissions every year. “The forest is failing as a climate protector,” says Susanne Winter, forest expert at the WWF environmental foundation. This is now official with the inventory. And of all things, it was turned off by weather extremes, which are increasingly associated with climate change.
This is unfortunate for the federal government. It has firmly planned for the forest as a “sink”, i.e. as a storage facility for carbon dioxide that is emitted in other areas of the economy. Since 2021, this has even been stipulated in the Climate Protection Act: By 2030, the forest should store an average of at least 25 million tons of CO₂ annually. Nobody imagined that it would instead become a “source” that would further reduce Germany’s emissions balance. “We still have a lot of work to do,” admits Agriculture Minister Cem Özdemir (Greens). He had already had to announce bad news about the forest in May, on the occasion of the forest condition survey. The diagnosis was similar: the climate is affecting the forest as a climate protector.
However, there is also some good news. The forest, which makes up a third of Germany’s territory, is changing and becoming more colorful. Since the last inventory, the proportion of deciduous forests in the forest area has increased by three percent; Which of course may also have something to do with the fact that spruce and pine trees in particular have fallen victim to storms, drought and bark beetles in recent years. The spruce, for a long time the dominant tree species, has lost around 460,000 hectares of area since 2012.
The traffic light is currently discussing a federal forest law
Instead, the pine tree is now number one in the German forest, occupying almost 22 percent of the area. “But it too is losing out in climate change,” says the federally owned Thünen Institute, which is leading the inventory. “Minus 41,000 hectares since 2012.” However, both pine and spruce are still mostly grown in “pure culture” in this country. This makes the forests even more vulnerable.
Özdemir also sees the findings as an argument for a new federal forest law, which the federal government is currently discussing. It should place greater emphasis on the “ecosystem services” of the forest and thereby shift priorities. The cabinet has now received a second, slimmed-down draft of the law, but this is also met with resistance from forest owners and the FDP. The Association of Family Businesses warns that there is a threat of “ideological guidelines for the choice of tree species” and restrictions on logging. It is now questionable whether the law will be renewed in this legislative period.
Meanwhile, the forest itself provides renewal. The foresters encountered a new generation of trees on three of the 11.5 million hectares of forest. In almost all cases it was a natural rejuvenation.