A protected tree in the Belgian city of Leuven – a Japanese honey locust tree named the 'Tree of Great Sorrow' – has a value of up to €2.5 million, according to research by environmental economists from KU Leuven.
The tree, located at the Atrechtcollege building on the well-known Naamsestraat in Leuven, has been listed as a protected monument since 1974. Now, environmental economist Sandra Rousseau, together with doctoral student Axelle Francx and master's student Karen Peeters, launched a study to determine the value of the tree.
"We presented 600 participants with a fictional scenario in which the tree was at risk of disappearing," said Rousseau. "With that knowledge, they could then decide whether they were willing to make a one-time voluntary donation for the tree's maintenance and protection."
The study follows the fierce protest from local residents in Antwerp last summer, after the city announced plans to remove 62 trees to build a new tram loop. The uproar led to a (temporary) halt to the felling and a formal notice from the city.
"It is mainly a matter of accurately estimating the value of these trees. That is often where things go wrong," Bart Muys, professor of forest management at KU Leuven, told De Morgen at the time.
History and local context
Now, two in three participants in the KU Leuven study were found to consider urban trees as 'very important', with half of them willing to make a one-time donation. The average donation was €17.50.
For people familiar with the Japanese tree, the donation amounted to around €21. Participants who were unfamiliar with the tree were also willing to donate, averaging just under €14.
"Based on these amounts, we were then able to calculate a total value," explained Francx. "A conservative calculation, limiting the results to the residents of Leuven, leads to a valuation of €1.3 million. If we broaden our scope and also consider the surrounding municipalities, we arrive at a valuation of just under €2.5 million for this monumental tree."
However, Rousseau pointed out that this does not mean that all protected trees in Flanders are necessarily worth millions of euros. "Our study paints a picture of this specific tree, with its own history and local context."
Credit: KU Leuven/Rob Stevens
With these results, the researchers hope to help governments, urban planners, and project developers in making decisions that could impact public green spaces.
When drafting construction or development plans, trees and other natural resources often lose out to more tangible financial arguments. The tools currently used by governments to calculate the value of nature do not adequately capture societal and subjective valuations, the researchers say.
The study's calculation takes this into account and can thus help cities and municipalities better assess whether there is support for projects that impact public green spaces.
