The Hidden Biodiversity Battle to Save Europe’s Forests

In Suonenjoki village, the Natural Resources Institute Finland (Luke) is enveloped by pine forests. The soil fertility is low, making pine the dominant species.

However, within the campus nursery, genetic material from across Europe, including European larch, wild cherry, and Scots pine, is cultivated. This diversity effort is part of the EU-funded OptFORESTS research project.

Seedlings are planted in 28 European locations, encompassing 12 tree species, to study species and genetic mixtures under various environmental and future climate conditions.

“Our aim is to diversify European forests and promote underutilized species,” stated Luke’s senior scientist Katri Himanen, overseeing seedling growth in Finland.

Santiago González-Martínez from the French National Institute for Agriculture, Food and Environment (INRAE), coordinating OptFORESTS, concurs. “We aim to guide the transition to more resilient and productive forest ecosystems,” he said.

Trees under pressure

Covering about 43% of EU land, forests are crucial for biodiversity, climate regulation, and carbon storage. However, they face increasing pressure.

Norway spruce forests in Germany, Czechia, and Austria have experienced massive dieback due to droughts and insect attacks since 2018.

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We want to actively guide the transition towards more resilient and productive forest ecosystems.

OptFORESTS addresses the urgent climate impacts on Europe’s forests. Researchers aim to utilize forests’ genetic resources, often overlooked, for adaptation.

“Genetic diversity acts as a biological backup, enhancing trees’ chances to withstand drought, pests, or disease,” González-Martínez said.

For instance, pine forests, rich in flammable material, burn intensely. Mixed forests with oaks experience less severe fires.

“More mixed forests could slow fire spread, enabling more fire-tolerant species to survive,” he said.

Diversification goes beyond a single area, explained François Lefèvre, a geneticist at INRAE.

“It enhances resilience at territory, landscape, and country scales. Genetic diversity must be considered across these scales,” he said.

From seeds to forests

Forests often consist of few species due to economic management preferences. Limited natural growth conditions can lead to vulnerable ecosystems.

Existing forestry relies on well-studied species like Norway spruce or beech. Most European tree species remain under-researched.

“Diversifying is challenging, requiring broader seed collection, nursery adaptation, and knowledge expansion,” González-Martínez noted.

Reproductive materials—seeds, cones, plant parts—are vital for planting decisions.

OptFORESTS evaluates the European nursery sector, projects future material needs, and collaborates with nurseries to broaden species production. This requires time and investment. As restoration grows amid climate damage, diverse planting material demand should rise.

Trial plots across Europe test genetically mixed forest growth. New tools aid forestry managers in selecting optimal species and genetic combinations for local conditions.

Research progress aids specific species. Norway now uses seedlings resistant to ash dieback. Slovenia restocks plantations with project-developed seed sources and seedlings.

“In the next decade, we’ll help foresters select better-adapted seed sources and management strategies, facilitated by genetics training,” said González-Martínez.

Beyond the lab

The initiative integrates genetic data into forest models, enabling simulation-based evaluation of strategies for long-term resilience.