Once there was a Japanese pagoda tree, that was 120 years old. It was the first tree planted in this park. One day it had to be removed, but to remember it, a beautiful bench showing the trunk of the tree formed of bronze was erected. To tell the story of the tree a sign was put near of it.
There is also a Serbian Wikipedia page about it. The English translation is:
"Sophora Bench Monument
The Sophora Memorial Bench is located in the Student Park, Stari Grad Municipality, in the center of Belgrade. In cooperation with JKP 'Zelenilo Beograd', sculptor Bogdan Vukosavljevic (1980, Belgrade), designed and made the first monument to the plant in the shape of a bench.
History
There used to be a Japanese sophora tree in the Student Park, which was cut down in 2008, when it was more than 120 years old. According to the board next to the monument, it was the first tree planted in this park. After a long series of years, it reached its physiological maturity, became ill at the root and had to be removed. It was 25 meters high , 4.25 meters in circumference.
Opening of the monument
On May 18, 2010, the promotion of this work of art was organized, which represents a park bench made of the material of a cut sophora. The pedestal of the bench was made as an authentic dwelling of a cut sophora and was cast in bronze, and around it were planted three young seedlings, which in that place represent an extension of its species. An info board is placed next to the bench.
On that occasion, the author stated: 'While making sculptures in wood and knowing all the beauty of processed wood, I came up with the idea to make a bench from healthy parts of the cut sophora. Having in mind the imposingness and the specific structure of the dwelling, I decided to remove the mold from the stump and the dwelling of the sophora with a specific prosthetic rubber, because that was the only way to preserve the authentic form of the tree itself. This project is specific in that it is the first monument in our area dedicated to one plant.'"
Translated from source: sr.wikipedia.org