Using data to increase forest diversity
We share our continent with forests. Around 43.5 percent of the European Union (EU) is covered by forests and wooded areas, offering a habitat to a wide variety of plants, animals, microbes and fungi. However, large stretches of these forests are under management. Only around 0.7 percent are free of direct human influence.
“Both in Austria and in Europe as a whole, most of the forest is under management,” explains Florian Kraxner, an environmental and forestry expert who heads the research group for agriculture, forestry and ecosystem services at the International Institute for Applied Systems Analysis (IIASA) and who knows that many of these commercial forests are not in good shape in ecological terms. On top of that, forests are also suffering from the consequences of the climate crisis. They are affected by drought, dryness, storms or the spread of two bark beetle species – the eight-toothed spruce bark beetle (Ips typographus) and the six-toothed spruce bark beetle (Pityogenes chalcographus) – against which certain tree species are increasingly defenseless. Conversely, intact forests provide recreation areas, food and timber, they clean the air, store water and cool the environment. Many also offer protection against rockfall and avalanches. If the forests suffer, we humans suffer too.
How can forests become healthier?
What can forest owners and policymakers do to increase forest biodiversity and climate resilience? Since April 2022, researchers from universities and institutions in Austria, Bulgaria, Finland, Germany, Spain and Sweden have been joining forces to find answers to this question. In the context of the EU-funded BIOCONSENT project, co-financed by the Austrian Science Fund FWF, they are trying to find practice-oriented solutions by harnessing new data models.
The situation is complex. No two trees or forests are identical, and environmental parameters, demands and management methods also differ from place to place. Around 16 million European forest owners and foresters influence how life in the forest develops through their daily activities. “Across Europe, there are also a large number of different policies that influence the management of forests,” explains Florian Kraxner. This complexity makes it challenging for policymakers to set clear targets for increasing biodiversity and for forest owners to take clear action in order to achieve these targets. Finding remedies to this situation required the researchers to work on many levels.
The forests are suffering
Despite global and EU policy goals, woodland biodiversity is in decline. The BIOCONSENT project is investigating how EU targets affect national legislation. The analyses provide important information for decision-makers and point out the hurdles to implementing forestry policy.
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Hungry for data
On the basis of a forest model involving machine-learning and AI that maps different forest types across Europe, Florian Kraxner and his colleagues modeled so-called socio-ecological forest systems. The types of forests taken into account by the research project included mixed forests in the German low mountain range, riparian forests with many beech and oak trees along the Rhine, as well as pine forests in the Catalan mountains and the Swedish lowlands. “The model is very data-hungry,” notes Florian Kraxner. In addition to the forest types, the model also incorporates biophysical data, such as data on hydrology, climate, weather influences, slope orientation, the growth rate of certain tree species, the condition of the forest floor and the composition of species. It also maps disturbances such as forest fires or pest infestations. These highly complex models always only show part of the whole picture, because, as Florian Kraxner puts it, “They ignore the human factor.”
The human factor
The human factor is crucial, because diversity is substantially affected by the time when and the number of trees that are removed or replanted, and by whether areas are taken out of use or deadwood is left in the forest. In order to map this situation, the project partners asked forest owners and foresters in Bulgaria, Germany, Catalonia, Poland, Slovenia and Sweden to complete questionnaires. They provided information about how they manage their forests – and said whether and, if so, which changes they would envisage to respond to political requirements or goals.
From the approximately 1,500 responses, the researchers distilled four “agents” who symbolize a certain type of forest owner categorized as multifunctionalists, optimizers, traditionalists, and environmentalists. The IIASA researchers then trained their forest model on the basis of these agents. “We want to explore what a forest landscape might look like if a group of agents were to actually implement the management proposals they have indicated,” explains Florian Kraxner. One such management method would be the ‘green path’. This is the name given to certain forest management practices in the project. They include large areas not being used for forestry, the planting of deciduous trees and later harvesting of existing trees.
The impact of the agents
“Our hypothesis was: the more similar the forests, the more similar the management practices and decisions will be,” notes Florian Kraxner. Was this hypothesis confirmed? What is it that influences how foresters and forest owners react to guidelines? An interim report from January 2025 provides a preliminary insight. The researchers found differences between the countries. The actions of Catalan forest owners, for instance, were also influenced by issues such as the infrastructure of forest roads, transportation and the availability of labor, while those played a lesser role in Germany. Nevertheless, the evaluation does show that the structure and type of forest seem to have a greater influence on forest management than the question of which type of “agent” manages it.
“The differences between the decision-making paths of individual forest owners do not seem overly pronounced. Their reaction to guidelines is similar,” notes Florian Kraxner in summarizing the preliminary results. The reasons for this are not yet fully understood. But, as Kraxner notes, “forest owners and foresters can take certain measures, such as harvesting either more or less timber or planting certain deciduous tree species. But at any rate they have to work with nature – no matter where they are.” The laws of nature impose certain rules, such as how fast a tree species will grow under given environmental conditions.
Forest policy
But there are other factors – such as the consequences of the climate crisis, the ecological state of the respective forests, as well as traditions and indigenous knowledge – that also affect human actions. The preliminary results from BIOCONSENT, which is set to run until the end of the year, suggest that the climate crisis, with its increased frequency of natural disasters, could trigger behavioral changes. Such disasters are becoming more and more common throughout Europe. In Germany, for example, more than 300 million cubic meters of timber have been destroyed by storms, droughts, pest infestations or extreme dryness in the past five years. And in Austria? The analysis and the survey suggest that the actions of domestic foresters are also influenced by ecological changes caused by the climate crisis. Personal values and motivations may also play a role.
What happens next in the project? One working group compared the modeling with actual national forest policies in the researched countries. The group is currently working on their analyses to develop decision-making tools for politicians at the EU and national level. This makes it easier to assess the consequences of political goals and objectives. “With this knowledge, together with the political guidelines, we can then say how the respective biodiversity targets could be achieved and how the path towards them would have to look,” says Florian Kraxner.
BIOCONSENT will be completed in December 2025. If consistently implemented, the knowledge gained can increase the diversity of Europe's forests. This, in turn, will not only be of benefit to forest life, but also to the European continent's human inhabitants.
Personal details
Florian Kraxner completed his doctorate in environmental sciences at Hokkaido University in Japan and had previously completed his master's degree at the University of Natural Resources and Life Sciences, Vienna, with a focus on forestry and torrent and avalanche management. His research focuses on sustainable land use, ecosystem services and carbon removal technologies. Kraxner is currently leading the research group for agriculture, forestry and ecosystem services at IIASA and is a visiting professor at Korea University. The BIOCONSENT project, which is part of the European research network ERA-NET, receives EUR 250,000 in co-financing from the Austrian Science Fund FWF.
Publications
Maximo YI., Hassegawa M., Nabau Joana et al.: Report on Improved Forest models with enhanced representation of behavior and behavioral change of forest owners and conservation managers, Zenodo Feb. 2025
Kraxner F., Zollitsch W., Kottusch C. et al.: Kapitel 5. Mitigation des Klimawandels, in: APCC Special Report: Landnutzung und Klimawandel in Österreich, Springer 2024
Gustavsson L., Sathre R., Leskinen P., Nabuurs G.-J., Kraxner F.: Comment on ‘Climate mitigation forestry – temporal trade-offs’, in: Environmental Research Letters 17 (4), 2022
