Hemauer / Keller
Alberi arrabbiati, 2025
Sound installation with texts in collaboration with Monica Cantieni; voice, Roberto Regazzoni. Dendrometer, soil water potential sensor, air temperature and humidity sensor for drought stress calculation.
Courtesy of the artists
There are three copper beeches in the Villa dei Cedri park, which are at least 200 years old. The trees were planted before the Gotthard tunnel was built, providing a rail link to Bellinzona, so they have already survived at length. In contrast to other tree species, such as the oak, the copper beech suffers particularly from the heat and does not react well to the increasing lack of water. Although considered a resilient and tenacious tree, such adversities cause its entire system to collapse at a certain point: this is manifest as discolouration of the leaf crown, which can already be observed in late summer. For this reason, the copper beech will probably disappear from dry locations in Switzerland, especially Ticino. So it is no wonder that it is becoming increasingly intolerant of humans.
Together with the writer Monica Cantieni, the Hemauer/Keller duo has given a voice to the mighty copper beeches in the museum park in 25 short texts describing the stress they experience from the drought to which they are exposed, and how they react. The texts are interpreted by the actor Roberto Regazzoni.
Changes in trunk radius can be measured in the microcrometre range with dendrometers, used scientifically to observe the well-being of trees. For example, it has been shown recently that trees grow at night, their trunk radius diminishes during the day then increases again in the nocturnal hours, but is reduced continually in drought conditions.
The TreeNet research network has been monitoring over 700 trees at more than 60 locations in Switzerland since 2011. One of these is now a majestic copper beech in the Villa dei Cedri park, which is being measured in collaboration with Roman Zweifel from the Swiss Federal Institute for Forest, Snow and Landscape Research.
Drought stress is calculated every 10 minutes. At values above 2, the tree suffers.
For more information: Christina Hemauer & Roman Keller
