An artistic research project conducted by the Institute for Computer Music and Sound Technology (ICST) in collaboration with the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).

ICST members of staff involved: Marcus Maeder, Jan Schacher, Daniel Bisig, and Beat Frei

Partners in the project: Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Dr. Roman Zweifel

During their forest climate research, Roman Zweifel and Fabienne Zeugin recently took measurements of ultrasound emissions from trees. When the water column in certain capillaries collapses in a severe drought, ultrasound waves are produced which are inaudible to the human ear but can be recorded. This phenomenon has been known for decades but the impact in terms of plant physiology is only partly understood. Therefore, from a scientific point of view, all the sound nuances are of great interest as they shed light on the phytophysiological interpretation. Thus, the scientific and artistic challenge is to optimize digital recording and reproduction technology so as to allow separation of the biologically induced acoustic signals in the ultrasound range as clearly as possible from the background noise. The better the results, the richer the artistic representation of the phenomenon and the more extensive our knowledge in the field of plant physiology.

However, the “trees” research project goes beyond "simple" ultrasound measurements and deals with the acoustic representation of multi-dimensional data relating to the climate and tree physiology: How can scientific knowledge and data such as the measurable effects of climate change be represented and interpreted artistically and made accessible to the general public? The tree sounds and acoustic representation of the measurements resulting from the study of the local climate of a tree or forest are being used to create a virtual acoustic environment in which the climatic condition of a tree, a piece of woodland or a group of trees is represented artistically and made into a model accessible to the general public. In contrast, the researchers at WSL are interested in a model that represents the climatic condition of not just individual trees but several trees, a section of woodland or various locations in the Alpine region. This is achieved, for example, through sounds which vary from tree to tree depending on the tree’s location and provides interesting perspectives and knowledge on acoustic events and their biological/climatic contexts in three-dimensional space or within a landscape through a spatial representation model in the form of a 3D sonic space representing a region or a landscape.

Publications on the ecological physiology and ultrasound emissions of trees

Correction of initial research results