Forest Day: Biodiversity takes center stage on March 21, 2020
On March 21, the traditional Forest Day takes place under the motto "Biodiversity". The day was established by the FAO (Food and Agriculture Organization of the United Nations) in the 1970s in response to the global destruction of forests. In Switzerland, around 1.28 million hectares of forest are cared for and managed.
It is not only on Forest Day that Christian Bottlang takes care of the forest in his forest district. Around 80 hectares, or ten percent of the total forest area, have so far been affected by bark beetles and storms. However, on the most severely affected forest areas, mostly a pure stand of planted spruce trees thrived, often planted by private forest owners generations ago. The trees stood in rows, growing close together. The spruces have been suffering increasingly from drought in recent years. The shallow roots cannot supply the trunk and crown with sufficient water.
About bark beetle & Co.
The trees are weakened and thus susceptible to damage, including bark beetles and storms. "Once the bark beetle has arrived in such a pure stand, it moves quickly," knows forester Christian Bottlang. The bark-breeding beetle bores into the bark, lays its eggs there and feeds on the bast, usually causing the tree to die. The infested trees must be felled and transported out of the forest as quickly as possible. This means that at present, affected areas are being cleared and the remaining stands of trees that are left exposed as a result are more susceptible to further damage, such as storm damage. The foresters have known about this for a long time.
On the areas that Christian Bottlang, as a forester of many years, manages and shapes himself in the forest district, pure spruce stands have long been a thing of the past. "Like many of my professional colleagues, I rely on diversity, on natural regeneration and regularly maintain the forest areas at intervals of five to ten years." Thanks to species richness and maintenance, the forest areas are more robust and healthier. The risk of damage is significantly lower.
Promote pioneer trees, combat neophytes
In private forest areas, the forester acts as an advisor. There is no actual management obligation for forest owners according to the Forest Act. They have to comply with obligations such as the ban on clear-cutting, the restocking obligation in protection forest, the use of site-appropriate plants or the marking obligation by the forest service for planned logging operations. Forest owners who have relied primarily on spruce - which was and still is an important tree species for the domestic sawmill and construction industries - in their forests are currently having a tough time. "Certain forest owners are truly shocked. In some cases, there are almost no trees left on their land," says Christian Bottlang. But the bare areas are now also clearly an opportunity, both for the forest and for its biodiversity. This is also the opinion of the Forest Department of the Office for Landscape and Nature of the Canton of Zurich.
"On the damaged areas, a sustainable, site-appropriate, diverse and ecologically valuable stocking from natural regeneration is to be created," explains the cantonal forest engineer, Konrad Nötzli. The existing guideline for the promotion of young forest maintenance in the canton of Zurich has been supplemented and now additional subsidies can be granted on damaged areas. The forest owners receive ten francs per area if they maintain and care for the bare areas in accordance with the guidelines. For example, pioneer woods such as birch, willow and poplar are to be promoted. These soft deciduous trees stabilize the forest floor and the humus layer, enrich the biodiversity of flora and fauna, and allow the regeneration defined by the forest itself to flourish thanks to sufficient light. Christian Bottlang also helps the areas with additional well-considered, small-scale plantings of oaks, for example.
He protects the small trees from deer browsing with wooden gates - naturally with wood from his own hunting ground. "We have already used a total of 70 kilometers of roof battens for the gates in the entire forest district." Here and there, one also discovers spruce again on the natural regeneration. "In certain areas, the entire range of trees thrives, even the silver fir finds its place." The forester is very pleased with the richness of species.
According to the guidelines of the office, the damaged areas, which are supported by contributions, must be intensively monitored by the forest owners for five consecutive years. The forester is clear: "We need patience, but now we have the opportunity to let a future-oriented, species-rich forest grow on the damaged areas. A forest that is also prepared for the challenge of climate change."
Forest day
On March 21, the traditional Forest Day takes place under the motto of "Biodiversity" takes place. The day was established by the FAO (Food and Agriculture Organization of the United Nations) in the 1970s in response to global forest destruction. In Switzerland, forests grow on around 1.28 million hectares. This area is cared for and managed by around 5,000 forestry professionals. Almost half of the animals and plants found in Switzerland are dependent on the forest, that is about 20,000 species. Thanks to near-natural, expert forest management, valuable biodiversity is preserved, despite the complex demands placed on today's multifunctional forest.
More about the "Forest Policy" of the Federal Office for the Environment FOEN can be found at here