Background

Changes in the landscape is already visible from afar. In some parts, especially around the Brocken massif and in the higher regions of the Harz, spruce trees are dying over large areas. Bare patches are appearing, dead trees line the roadside, which can contribute to a depressing atmosphere. However, if you look closely, you will discover fresh green underneath...

The landscape of the Harz Mountains, which for centuries was characterised by pure spruce forests, is changing. Spruce was originally planted as fast-growing wood to be used in mining. In the post-war period, more wood was needed for reconstruction, for heating and also for part of the reparation payments. As a result of the severe overexploitation of the forests from the 1930s until about 1950, approximately 140,000 ha of bare forest was created in Lower Saxony alone. In order to reforest these areas, great efforts were made by foresters and so-called “Kulturfrauen” (culture women). They worked hard and for low wages to reforest the forests.

Only spruce seed was available in sufficient quantities in the Harz Mountains. Thus, spruce became the “Brotbaum” (bread tree) of the region and was also planted in locations where it is not actually native. This is an area where deciduous trees would naturally grow - beech mixed with maple, birch, ash, and other tree species.

The hard work of the "culture women" was appreciated with a special coinage of the West German 50 pfennig piece of the time. It showed a kneeling woman planting an oak tree.

Weather extremes such as storms and drought have severely affected trees in recent years. These weakened trees now lack natural resilience.

Spruce dieback is triggered by bark beetles, which eat their way through the conductive pathways of the spruces. Healthy spruce trees can ward them off with tree resin - a natural mechanism that no longer works due to the prolonged drought and heat of the past summers.

Even a small number of bark beetles causes the spruce trees to die. In good conditions, they can reproduce en masse. A female can produce hundreds of thousands of offspring in just one year. However, not only spruce trees are affected by tree death. Deciduous trees such as beech and ash are particularly widespread in the southern Harz. They are just as susceptible to diseases and parasites due to the climate stress.

In view of the acute and rapid changes in the forest, there has been hefty debate, particularly in social media about who or what is responsible for this situation.

The fact is that we all share responsibility. Even if there is controversy about how strong the influence of humans on the climate is. The accumulation of climate records in recent years is a clear indication of this.

The speed of change is increasing and overtaxing the adaptability of many tree species. Blaming the Harz National Park, where only a few areas are actively forested, is also absurd. It is more important to create solutions together.

There are various protected areas and forest zones in the Harz. In the centre is the Harz National Park around the Brocken massif. The "Harz" and "Südharz" nature parks and the Karstlandschaft Südharz biosphere reserve surround this area. While spruce forests predominate in the upper and high Harz, beech, deciduous and mixed forests can be found at lower altitudes.

Not all areas are affected by the massive tree death. Therefore, it is important to take a differentiated view of the forest change in the Harz Mountains.

The current situation is dealt with differently in the different areas of the Harz.

In some areas, nature is largely left to its own devices, in others the interests of sustainable forestry are taken into account.

For decades, forestry has been following the basic idea of sustainable and near-natural forest management on an ecological basis. Within the framework of Lower Saxony's LÖWE programme (Langfristige Ökologische WaldEntwicklung - Long-term Ecological Forest Development), forest change has been promoted since 1991, i.e. the conversion of monocultures to climate-stable mixed forests. For example, in the last 25 years the proportion of mixed stands with deciduous trees in Lower Saxony has grown from 31% to 58.

But extreme situations with heavy rain, storms, and drought of 2018 and 2019 pose additional challenges for foresters. In commercial forests, trees infested by the bark beetle are felled and transported away almost around the clock. Aisles are created between infested and healthy areas. Subsequently, extensive reforestation is carried out. In this way, millions of saplings were able to be replanted in the Harz Mountains even during the difficult period of 2018/2019.

State forests are to become more stable, productive, aesthetic as well as more natural with a diversity of tree species appropriate to the location.

National parks all over the world go by the motto "Let nature be nature" and so nature is largely allowed to develop freely in the Harz National Park. The former commercial forest is transforming into a wild natural forest. A high structural diversity of trees of different ages and sizes as well as large amounts of deadwood in uneven stages of decomposition characterise the primeval forest in the middle of the Harz National Park. The fact that this change is currently proceeding rapidly in some areas often seems strange to the observer. But nature follows its own laws. What appears dead and dying is more dynamic and alive than before. Spruce trees are gradually disappearing where they are not native. Deadwood, in which bark beetles can no longer survive, remains in the forest as an important habitat.

Tree trunks and the substances stored in them are becoming the foundation for a new forest generation. Likewise, the number of animal and plant species is increasing significantly. Rare and endangered species are also finding habitats here and are returning.

Nevertheless, there is also active intervention in parts of the Harz National Park, e.g. to secure paths and roads and to protect adjacent commercial forests.
In addition, the national park supports the return of the original native deciduous trees in some areas through planting.
The resulting wild natural forest will look different from the surrounding commercial forests. From 2008 to 2018 alone, around 4.3 million copper beech and other native species were planted in the national park forests.