Lebanon cedar? "No way"

There is no question that the forest is not doing well - gaps, windthrow and sparse crowns everywhere. "Weather extremes" and their consequences, such as pest infestations, "continue to have a major impact on the Hessian forest", writes the Hessen-Forst state enterprise with reference to the recently published Forest Condition Report 2023. Eleven percent of the forest is severely damaged, more than three times as much as the average for the years 1984-2023.

Just in time for spring, this issue (publik 2024/1) focuses on a number of projects at the University of Kassel that deal with the future of the forest or the benefits of trees. We spoke to Prof. Dr. Ewald Langer, head of the Department of Ecology at the University of Kassel and a proven expert on local forests, to help put things in context.

Ewald Langer: The dieback is already massive, and that is frightening at first glance. Around Kassel, for example, there are hardly any spruce trees left; almost all of them have died in recent years. But it has to be said: spruce trees don't really belong here. They were planted to provide wood quickly. The natural forest in northern Hesse is a mixed beech forest, and it will grow back. Unfortunately, it will take 30 to 40 years.

Langer: If open spaces are left to their own devices, a natural consequence emerges: first shrubs such as brambles colonize, in whose protection pioneer trees such as birch grow and later dominant species, in our case beech. This can be observed in the Bavarian Forest National Park. Large areas there fell victim to the bark beetle in the 1990s, but a new, stable forest is now growing there.

Langer: Absolutely not! Some people would like to create a Mediterranean forest, but completely overlook the fact that we shouldn't just focus on the dry summers. Many southern species, for example, would not be able to cope with the winter frosts.

Langer: That's right, the forest is a system that also includes other plants, animals and fungi. Fungi are rarely talked about, although they permeate the entire forest floor and supply the trees with nutrients and water. Other fungi decompose dead wood and thus keep the nutrients in circulation. None of this can simply be transplanted.

Langer: Our students complete their practical mushroom course there and survey the population in certain areas. There are at least 1,300 species of fungi and 2,500 species of beetles in the Kellerwald alone. North of Kassel, in the primeval forest at Sababurg, there is even the hermit, a very rare beetle that lives in wood and often does not leave its burrow for the rest of its life. You can even smell it, it has a fragrant scent.

Langer: Take line 8 to the terminus. The Hessenschanze is particularly beautiful in spring. This is one of the few areas in our region that has calcareous rather than acidic soil. As a result, wood anemones, woodruff and orchids grow there ... beautifully.

This article appeared in the university magazine publik 2024/1. Interview: Sebastian Mense.