SOM II, subproject: Historical tree gets connected
For over 150 years, the former beech tree stood in the courtyard of the Cathedral School and in December 2019 a new one was planted. The tree is historic — not only because it is an important symbol of the school, but also because it is the first large tree that Lund Municipality chose to monitor with buried moisture sensors. The technology of sensor monitoring of trees has been developed in Lund as part of the SOM project.
Finanisär
Since 1857, Katedralskolan in Lund has had a care tree in the schoolyard. The tree was an important part of the school, and each year the dates of when the buds burst and when the tree was fully set were recorded. In 1887, the school began a tradition of celebrating the tree with speeches and singing through a ceremony in the schoolyard. But the tree became old and infested with fungus and in 2012 it was taken down. The 11th of December 2019 became a new historical date for the school as the new tree was planted on this day. At the time of planting, the tree was already 40 years old, nine meters high and weighed about 6 tons.
The tree was brought from Germany where it had been replanted eight times to stimulate the formation of small fine roots that make it withstand a repotting well. The tree and the transport to Sweden cost 217,000 kronor.
“This tree has great cultural historical value but is of course also valuable for the environment and accounts for many ecosystem services,” says Barbro Lange, project manager and landscape architect at Markentrepreneurad in Lund Municipality in a 2019 interview. We hope this tree will last at least as long as the previous one.
The tree is important to Katedralskolan and Lund but is also historic for another reason — it was the first large tree that Lund Municipality chose to monitor with sensors. In the pit, sensors were dug down already at the time of planting. Anders Hedberg from Sensefarm was on site to put two sensors in the bottom of the planting pit and two sensors about 30 cm below ground level.
“All users at Markcontracad can see through their mobile phone or computer that moisture is adequate at the roots and by having sensors on two levels they can also see what happens when it rains,” Anders Hedberg of Sensefarm told us in an interview in December 2019. Together with Veab in Gothenburg, we have worked in a similar way to monitor the management of moved trees with sensors in connection with the construction of the West Link in Gothenburg with good results.
The sensor values are sent via Lund's LoRa network, which at the time of planting had been taken over by Kraftringen. To strengthen the signals, a new base station was placed nearby. The values allowed care managers to then determine how much extra water the tree needs.
The work is a consequence of the sub-project Green Space Management within the SOM project, which is part of the strategic innovation programme for the Internet of Things, IoT Sweden, which is funded by Vinnova. Anders Trana at Future by Lund was the project manager for the entire project. The project started on 1 September 2017 and ran until December 2020.
