Future Forests – How Can We Make Forests Fit for the Future?

We demand a lot from our forests: We want them to serve as recreation areas and as places for experiencing nature. They have to provide intact habitats for a multitude of plants and animals. Trees and forest soil need to store CO₂ and water, now more than ever in times of climate change. And on top of all that, forests must also be economical and provide us with wood. Scientists call these the ‘ecosystem services’ that forests provide for us.

Yet it is uncertain whether forests can continue to serve their many functions. They are being damaged by climate change in the form of droughts and storms. Non-native animal and plant species are spreading, as native species disappear. These changes are happening so fast that natural adaptation processes are often not enough to ensure the continued existence of healthy and species-rich forest ecosystems.

Artificial stress for trees

A former hangar at the Freiburg airfield houses six large enclosures measuring more than three meters in height – so-called ecotrons. Oak leaves can be seen through the viewing panels in the doors, lit brightly by LEDs. Young oak trees are growing in real forest soil here, four in each ecotron. Fabio Scarpa is a doctoral candidate and is conducting an experiment with the ecotrons: ‘We’re conducting basic research here to understand how oaks react to repeated periods of drought’, he explains.

The oak trees will have to endure a great deal in the coming weeks. They will be subjected repeatedly to heat and water stress. It is possible to precisely simulate different environmental conditions in the ecotrons: extreme heat or cold, drought and humidity, varying light conditions, and different CO₂ concentrations in the air. The ecotrons are also equipped with sensitive instrumentation for measuring how the plants react to this stress – such as which organic gases they emit via leaves and soil and whether they gain or lose weight.

Simulating future scenarios on virtual forests

Change of location: The developer Paul Lakos stands on a metal platform in a room at XR Future Forest Labs in the Freiburg city centre. He’s wearing virtual reality glasses and is looking around. His colleagues can follow what he sees through the glasses on a large screen behind him: On it, Lakos is in the middle of a virtual forest, high up on the platform of a measurement tower.

Lakos is an XR developer. XR stands for extended reality, a combination of the real world and digital elements. The virtual forest Lakos is observing is not a figment of his imagination but the ‘digital twin’ of a real piece of woodland located a good 30 kilometres north of Freiburg. There, in the real forest, scientists from the Collaborative Research Centre ECOSENSE are testing how to measure the stress reaction of the trees to climate change with the help of a network of microsensors.

Every single tree in the ECOSENSE test forest has its exact counterpart in the virtual forest. The XR team created the digital twin by scanning the real piece of woodland from above with a drone. A special AI then used the data to calculate which tree stands at which location, what species it belongs to, and how large it is. In this way, the scientists can reconstruct an entire forest tree by tree on the computer.

‘With the help of XR technology, we’ll bring forests from every corner of the world right here to the faculty. Our students and researchers will then be able to take virtual field trips through the forests’, explains Christian Scharinger, head of the XR Future Forests Lab.

But the technology can do even more: ‘We’re going to make the invisible visible’, says Scharinger. Soon it will be possible to display data on individual trees in real time – for instance data on a tree’s CO₂ exchange with the atmosphere or on its water intake, measured many kilometres away by the microsensors developed by ECOSENSE.