At the Diakonhjemmet in Oslo, they believe that old trees are important, and on their grounds there are five ancient oaks of great value. When they planned to build a new nursing home, they discovered that the building would shade a small clump of trees where the area’s oldest oak tree stands. The tree is several hundred years old, and over three meters in circumference. Shadowing this would have consequences. Kristin Moldestad is an arborist, and works at the consulting company Cowi taking care of the trees in the building project for the Diakonhjemmet. Photo: Lars Håkon Pedersen / news – Different organisms live in the bark of the trees, and they depend on the sun, especially in the spring. And in order to safeguard the living conditions for those living in the oak, the nursing home was reduced by one floor, says arborist Kristin Moldestad. The price tag for changing the building will be several million kroner. Experts estimate that an oak tree can house up to 1,500 different species of insects, fungi, moss and lichen, and the tree species is therefore assessed as a so-called selected natural type, which must have stronger protection than other species. The bark of an old oak tree is home to a high number of species of insects and other organisms. Photo: Lars Håkon Pedersen / news This year we have had several heat waves that have been even more powerful than before, with heat records in Europe. This gives the large, old trees an increasingly important role. Old trees provide shade and they catch rainwater that is channeled into the ground. They produce oxygen and they capture CO₂. They create good urban spaces and well-being for people, in addition to being a home for many other organisms. Want to take care of important trees For the developer, it was no easy matter to adjust the plans, although they eventually realized that they had to do it. Jon Solsrud is the project manager for the nursing home, which is being changed to provide sunlight for trees and insects. Photo: Lars Håkon Pedersen / news – We have to take care of these oaks of ours. Nursing homes are a lot of logistics, and we need whole, good floors. But we found a good solution, says project manager Jon Solsrud at Diakonhjemmet. The solution was to reduce the height of the building and change the building mass. In the same way, they chose to dig up asphalt along a tree cluster consisting of maple trees to check how far their roots went. – This meant that we had to change the route for a power cable, which resulted in both additional work and additional costs, says Solsrud. The deacon home took up asphalt and checked the root systems of nearby trees. This meant that they had to choose a different route for a power cable. Photo: Lars Håkon Pedersen / news – Can profit from spending money on trees If important trees are to be preserved in a development, it could go beyond the utilization of a property, where costs and profits are central. Nevertheless, community director of the Building Industry’s National Association, Jørgen Leegaard, believes that there is an increased understanding of this. Jørgen Leegaard in the Norwegian Building Industry Association believes that several builders are concerned with preserving trees. Photo: BNL – Someone will be interested in removing a tree or two that stands in the way of being able to make an extra profit. At the same time, there is a fairly large understanding in the construction industry that we must contribute to reducing the footprint from production, and taking care of trees is part of that, he says. Forest ecologist and researcher Ulrika Jansson at the Norwegian Institute for Natural Research, NINA, walks along a footpath on Ullevål in Oslo. – Here there are still forests and old trees, despite the fact that it is between the subway and the buildings. – A tree is a block of flats, says forest ecologist and researcher Ulrika Jansson at the Norwegian Institute for Natural Research. Photo: Lars Håkon Pedersen / news Jansson believes that builders will in any case benefit from taking care of trees when new commercial premises or homes are built. – Prices for homes in areas where there is a lot of nature and trees are higher, she claims. Jørgen Leegaard in the Building Industry agrees. – Good housing quality gives value in the market, he says. A tree is a block of flats But insects, lichen and moss must also have good living conditions. And it is in the oldest trees that they thrive best. Ulrika Jansson points out that the bark is a haven for many living creatures, and that old trees have more room to offer than younger trees. – It has a greater value, because it has more habitats. You can think of it as a block of flats for many thousands of individuals, while a younger tree houses only a few hundred. Jansson further points out the obvious; that a hundred-year-old or even older tree has taken the same amount of time to become that old. – It is important that when you think about planting trees in the city, it is not a short-term replacement for the old trees that are already here. Big plans for tree planting Oslo currently has over a million trees in the urban zone, and a plan to plant 100,000 additional trees this decade. A young tree is planted together with a dozen others at Tåsen School in Oslo. It is part of the municipality’s large-scale plan to increase the number of trees in the city. Photo: Lars Håkon Pedersen / news So far only a few thousand have been planted, but it will increase, says head of the Oslo Trees project, Hanne Johnsrud. – We move slowly at the start, it is important to plant the right tree in the right place, and the tree must have the right growing conditions. We also have to get the trees produced, and have collaborations with nurseries that grow them for us. As 2030 approaches, the plan is for 20,000 trees to be planted a year in Oslo’s construction zone. Other Norwegian cities also respond that they have clear plans and visions for their urban trees: In Bergen, trees must have a significant place in the cityscape, and trees must be looked after where they have value. The ecological effect of the urban trees must be utilized, and trees that are common must be replaced. The number of trees in the city must be increased. Stavanger must be a green city with a varied and species-rich population of city trees with intrinsic value both from a climate and from a living conditions perspective. Trees are the city’s green infrastructure and are considered as important as other infrastructure in the city. The number of urban trees must be increased significantly. Trondheim aims to preserve the natural state and ecosystems in the city. There are requirements to plant trees in new buildings, and targets for more green roofs with vegetation on them. The city also protects green lungs from development. A total of 3 billion trees will be planted throughout the EU by 2030, trees that will be added to the natural growth. It will happen as part of what is called the European Green Deal.
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Preserves old trees in the city
