A laboratory in the forest

In the open-air laboratory at Puéchabon, researchers simulate drought to study the ecosystem's behavior in the face of climate change.

30% less rain: that's what climatologists are predicting for the year 2100. How will the forest react to this increase in drought? To find out, the Centre d'écologie fonctionnelle et évolutive has transformed the Puéchabon holm oak forest, some thirty kilometers from Montpellier, into a veritable open-air laboratory. To simulate drought, the researchers have installed a system of gutters that collect rainwater before it infiltrates the soil. They also have a mobile roof of over 200 m2 that can be moved over the forest to deprive it of rainfall.

The forest is studied from every angle, thanks to a walkway installed in the canopy that allows scientists to take measurements on leaves and branches, while a "flux tower" continuously measures the forest's carbon and water balance. "These devices enable us to study the ecosystem's behavior in the face of climate change," explains CEFE researcher Jean-Marc Limousin. How will the holm oaks fare in the dry climate of 2100? "For the moment, they're adapting. In particular, we've noticed that they're reducing their number of leaves to sweat less and save water".