“Forest fires and the next heavy precipitation are currently more of worry for me than climate change.” Roland David is Head of the Forestry Office in Ticino and Mayor of Faido, where, shortly before Easter, 60 hectares of forest burned down. He has at the moment literally burning questions about what “his” forest might look like in 80 years time – which is exactly what the fourth “Forest Test” – this time in Bellinzona at the end of May 2017 – is about. More precisely, it addresses the question of how forest managers can, in practice, take into account climate change. The participating forest experts are therefore “testing” a tool to help decision-making in silviculture, which was developed in the Research Programme “Forests and Climate Change” by WSL and the Federal Office for the Environment (FOEN).
“Extreme events do indeed have a marked impact on the forest,” says Peter Brang, Joint Head of the Programme at WSL, confirming Roland’s concern. “But it is just after such a forest fire that it is good to know which tree species could grow on this site when it gets warmer.” The findings of the Research Programme indicate that trees that germinate today will already be living in a very different climate by the time they are middle aged. Climate change is taking place so quickly that is questionable whether the forest will continue to be able to perform its many functions without targeted silvicultural interventions.
Tree species are moving up
The Forest Test participants discuss in groups at different sites which interventions are suitable for converting the forest stands of today into stands adapted to the climate of tomorrow. For this they use the new forest management decision tool, which is based on the Canton’s descriptions of the forest sites available that have proved useful for silvicultural planning.
Here at 1000 m a.s.l., the test participants are standing in a typical fir-beech forest near Monti di Ravecchia high up above Bellinzona. This forest site will, according to the modeling, develop under the influence of climate change into a holly-beech forest, like the one growing today a few hundred meters lower down. The most important finding from the group work is that beech will continue to occur. In addition, sessile oak should be promoted as a drought-tolerant species to ensure the forest can withstand drought better, and the goal should be a mixed forest that is less susceptible to pest damage. Up here, however, the numerous wild ungulates mean that expensive protection measures will be necessary to prevent browsing.
At a second Forest Test site near Sementina close to Ticino’s valley floor, introduced tree species must also be considered in decision-making since forests similar to those growing today around Genoa on the Mediterranean coast are likely to grow best here in future. “Each time we make an intervention today, we need to check whether something can be done to help the forest adapt to climate change, for example, by promoting the diversity of tree species,” says Peter Brang in summary. Rolf Manser, Head of the Forest Division at FOEN BAFU and also a participant in the Ticino Forest Test, adds: “Our experiences with the Forest Tests are helping us greatly in integrating the research findings in forestry practice and training.” (Martin Moritzi, Diagonal 2/17)