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The UNIL Ecotron “Terra” is a climate simulator that allows precise control of environmental conditions such as solar radiation and precipitation, as well as groundwater dynamics.
This system makes it possible to observe the soil–plant–atmosphere continuum under laboratory conditions, and investigate the transport of water and solutes in these conditions. Experiments can last from a few days to several months.
Within the Ecotron, a wide range of climatic and meteorological scenarios can be recreated: from dry to wet, from warm to cold, from a light breeze to a rain storm, from strong sunlight to high humidity, and from high to low groundwater levels.
Experiment setup
The UNIL Ecotron has a 3 m³ compartment in which three vegetated soil columns, called lysimeters, are installed. They are then exposed to programmed climatic variations in: light exposure, air temperature and humidity, rainfall, soil temperature, and groundwater regime.
The lysimeters of the “Terra” Ecotron can accommodate up to 6 sensors (humidity, soil matric potential, pH, redox potential, water isotope probes, suction probes) at 8 different depths, enabling precise and continuous monitoring of the processes involved.
Lysimeters can be filled with a single block of soil collected directly in the field, or with repacked sediments. In the example below, the lysimeters are filled starting with a gravel filter, followed by the soil in which the sensors are installed, and finally a grass cover.
The lysimeters can then be installed inside the Ecotron to start an experiment.
Vegetation development inside the Ecotron can be easily monitored using a time-lapse camera. The example below shows the evolution of a grass carpet over 40 days.
Progress and Ongoing Experiments
Spring 2026: First tests
The very first tests on the Ecotron were carried out by a civil servant, Sébastien Rogers. The objective was to test all components together and evaluate how precisely the instrument achieves the target climate.
