A nursery for tomorrow's forests

Not only the plants, but also the five employees of the public tree nursery in Flaxweiler were already groaning under the heatwave by 11 o'clock in the morning. Forester Thierry Diedenhofen measures the ground temperature with a laser thermometer: 52.3 degrees. The team has been watering since six o'clock this morning to prevent the water from evaporating straight away: during the heatwave, they need roughly as much water in a single day as they would normally use in a whole week. "It's all spring water and rainwater, " emphasises Diedenhofen, whilst a tractor takes the next load to the tank. One of the irrigation system's pumps broke down at the start of the week – fortunately, two had been installed straight away, precisely for this eventuality. "Here, you have to be a gardener, a logistics specialist, a tradesman, and a civil engineer all at once, " says the head of the tree nursery – himself a former forester – with a smile: "We've got a brilliant team who are willing to come in earlier or stay later if necessary."

The site, covering around 2.4 hectares, is the state's last remaining tree nursery, following the closure of the other five at the turn of the millennium. The decision at the time was the result of a shift in thinking: natural regeneration was regarded as the best approach to preserving the state's forests. If you leave the forest more to its own devices, nature will find a way. So the theory goes. 

A change in strategy

However, the reality of climate change – with its extreme heatwaves and droughts, followed by flash floods – has pushed this approach to its limits. The forest, where time is measured in centuries, simply could not keep pace with the changes. Combined with the artificial monocultures across large parts of the country, this has led to the widespread tree die-off we are seeing today. It quickly became clear that the changes caused by humans now seem to require some human intervention to restore balance. At least if we want to preserve forests more or less as we know them.