It’s not good news: the city gardening company is planning to fell 261 trees in Basel. What are the reasons? Our editor Martin Zwahlen examines this question in his article – and spoke to the city gardening department.
Trees are valued by the population in urban areas and fulfill a variety of functions. They provide shade on hot days, offer protection when it rains and purify the air. They make an important contribution to ecology and, with their different typological arrangements, are important for orientation in urban space. However, the trees have specialized in their development for other conditions. In the street space they are exposed to many stress factors: limited root space, waterlogging in the tree pit, longer dry periods, water pollution from tire abrasion, road salt in winter and the repetition of the same species in a small space increase the risk of pest infestation. All of these are reasons why urban trees only have an average lifespan of 50 to 80 years.
Overview of the tree register in Kleinbasel. Existing trees are marked in green and those intended for felling are marked in red.
It is noteworthy that in Basel-Stadt trees with a trunk circumference of more than 90 cm have been protected since 1980, and in certain tree protection areas from 50 cm onwards, trees have been protected. In one Media release has informed the city gardening department of its plan to fell a total of 261 trees. Due to the legal situation, a felling permit is required for 187 of these trees. The applications are published publicly in the cantonal newspaper – and must be approved by the building and hospitality inspectorate.
Detailed tree register information, using the example of a white elm in the popular three-rose plant
Every request must be justified. Some reasons are mentioned in the media release. Many arguments are understandable, such as pest infestation, maldevelopment, death of parts of the crown or natural weakness with age. The term “lack of development potential” is also mentioned as a reason for the felling. What does that mean specifically? We asked the city gardening department.
The trees submitted for felling are marked in red and receive a detailed explanation. You can see a Norway maple tree along the Lower Rhine Trail.
“The term usually describes a young tree that cannot develop into a large, healthy and stable tree due to mechanical, natural or climatic influences. In such situations we decide [die Stadtgärtnerei]us for a 1 to 1 tree replacement or, in the case of climatic influences, even for a change of tree species,” wrote the city gardening company in response to our request. Mechanical damage is the result of external influences such as collision damage to the trunk or the crown. After a storm, irreparable damage could occur to the crown or central shoot, which is considered a natural reason for the felling. Local climatic changes such as heat accumulation, which inhibit the growth of trees, are often a so-called climatic reason for felling.
On-site inspection!
A small selection of trees to be felled…
Leather hawthorn, trunk circumference 63cm (replacement planting)
Reason for felling: Disproportionate preservation
Massively crooked position, danger of tipping over. Root injuries on the tension side.
Canada poplar, age 84 years, trunk circumference 247cm
Reason for felling: Danger, large cavities in the crown. Risk of breakage.
Simon’s poplar trunk circumference 34cm (replacement planting)
Reason for felling: danger, weak growth. Imbalance with poor development.
An example of these climatic changes are the planned tree felling and replacement planting on Flughafenstrasse and Neudorfstrasse. Historically, tree avenues and rows of trees were planted with a uniform tree species. A well-known example is the plane tree avenues that were created by Napoleon. However, it has been shown that this monotonous selection of species is particularly susceptible to diseases, fungi or pest infestation.
An example of this is Flughafenstrasse and Neudorfstrasse: Norway maples have lined both streets for around 24 years. Unfortunately, it has been shown that this native tree species is not developing as desired in these locations, despite its previously known resilience. On the contrary: the trees die in the crown, severe cracks form on the trunk, fungal infection is the result and there is a risk of breakage. The city gardening department therefore decided to change tree species. In January 2025, nineteen of the remaining Norway maples must be removed due to the damage mentioned. In autumn 2025, young, healthy and resilient alder, oak and hop beech trees will be planted in the same place. With this change in tree species, the city gardening department is convinced that the crown volume will be balanced again within the next five years.
Are there any fellings in my neighborhood? The 187 trees with requests for felling that require approval can be viewed on the Internet under MapBS and under the term “Urban Tree Stock”. For each tree, the tree species, trunk circumference, reason for felling and information on replacement planting are available. The locations of the trees can be seen on the public map from MapBS. The informative transparency of the city gardening department is exemplary – even if the individual fate of every felled tree is a small downside.
Article: Martin Zwahlen / Architecture Basel
Those: Media release – Construction and Transport Department
Section 1: Urban Tree Felling and its Implications
– Why do trees need to be felled in urban areas?
– What are the key reasons behind the felling of 261 trees in Basel?
– How do stress factors like limited root space and water pollution impact urban trees?
– What measures have been taken by the city gardening department to protect existing trees?
– Can you explain the importance of tree replacement when felling is necessary?
Section 2: The Role of Tree Species in Urban Landscapes
– How does a uniform planting of one tree species impact the health of a tree population over time?
– What are the potential consequences of changing tree species in urban areas?
– What has been the experience with the Norway maples along Flughafenstrasse and Neudorfstrasse in Basel?
– Why is it important to balance the crown volume of trees in urban areas?
Section 3: Public Transparency and Involvement
– How does the city gardening department involve the public in tree felling decisions?
– How can residents keep informed about tree felling plans in their neighborhood?
– Is there a risk of public backlash when it comes to urban tree management?
– Do you think public input is valuable in the decision-making process for urban forestry?
