The future of forests

But are forests really that fragile? "It is a complex environment, about which we know a lot, but of which there is still much to discover. Certainly, it is an ecosystem that is fragile by nature, but it is also naturally adapted to reacting to disturbances that change its balance," explains Marco Mina, forest ecologist at Eurac Research's Institute for the Alpine Environment. "The problem obviously arises when the effects impact people, for example when an entire community has to evacuate because of fires or when the so-called ecosystem services - that is, the resources that the forest offers, including several economic resources - are lost."

Vulnerability depends on many factors, including the socio-economic fabric of the area where the forest grows, its level of exploitation and its proximity to humans. A recent study has shown that in the United States the forests most affected by the action of exotic pathogenic insects were those near major ports, such as Boston, because these insects travel with goods. Similarly, fires are more common near urbanized areas, where the likelihood of an initiating factor increases.

"Sometimes forests are more fragile because of what we’ve done to them," says Marco Mina. One example is precisely the forests of the Asiago Plateau, in the Venetian Prealps, that were hit hard by October 2018’s extreme phenomena. "These are a typical example of secondary formations, in the sense that they were replanted after World War I, resulting in a pure spruce forest. This type of forest is definitely more vulnerable in the face of extreme winds, such as the ones that occurred." In fact, pure spruce stands grow faster and their timber products are more easily worked and transported than those from primary forest that has developed through natural processes. Primary forests have a more heterogenous structure and are typically comprised of several species such as spruce, fir, beech, larch. A pure spruce forest undoubtedly has more economic advantages, at least in the immediate term. For the same reason, spruce forests have been planted in many lowland areas in Central Europe, even though it’s not a place properly suited to this species from a climatic perspective. With the drought of 2018, these ecosystems experienced decidedly high mortality among tree species.

Mathematical models of this type are tools that can give valuable recommendations "Their reliability resembles that of the weather, obviously at very different time scales," explains Marco Mina, "At 10-20 years they offer fairly precise forecasts. On longer time scales, which reach a century, uncertainty increases. But they still manage to provide useful indications at a general level: just like long-term weather forecasts, they offer general information about trends and how the weather will develop."

"Contact with local governments is invaluable. Not only because they provide data essential to initialize the models, but also because they tell us what the most current issues that we could try to answer with our modeling studies are," comments Marco Mina. "It is encouraging to see how local authorities are interested in the final product and how they will be able to use it. For our part, understanding their needs allows us to calibrate the models even better for very practical applications." The third phase of the project will involve the creation of scenarios that go beyond climate change and describe the socio-economic management of the forest. Models that quantify - including economically - the ecosystem services that the forest provides to communities and the resources needed to manage these areas. "Simulating such scenarios will allow us to understand not only how much it costs to protect the forest, but also how much it costs not to protect it.”