Climate Change Threatens the European Forest Carbon Sink, But Assisted Migration Offers Hope
The new study Assisted tree migration can preserve the European forest carbon sink under climate change | Nature Climate Change published by SUPERB researchers Debojyoti Chakraborty, Albert Ciceu, and Silvio Schueler today in the journal Nature Climate Change reveals that simply planting more trees in Europe won’t be enough to effectively combat climate change and preserve the continent’s terrestrial carbon sink. Researchers from the Austrian Research Centre for Forests (BFW) and international collaborators stress the crucial role of “assisted migration” – a strategy of selecting tree species and seed sources that are best adapted to future climate conditions.
The study, the largest of its kind ever conducted, analyzed data from 587 forest provenance trials across Europe, encompassing 2,964 different seed sources from seven major tree species. Provenance trials are long-term field experiments that evaluate the performance of trees originating from different geographical regions. Data from such experiments, collected over several decades by generations of researchers, provide valuable information about local adaptation, growth, and survival of tree populations.
For the present study this information was integrated into advanced models to project how the carbon sink capacity of seven major European tree species will change over the next 60 years under different climate change scenarios.
The results were clear: climate change will significantly alter the suitability of different European regions for various tree species. While this necessitates a shift from predominantly coniferous to more resilient broadleaved species, the study highlights that simply switching species isn’t enough.
“Our models show that if local seed sources continue to be used in reforestation and forest restoration, the annual carbon sink of European forests could decrease significantly by the end of the century, even if we transition to more climate-resilient species,” explains Debojyoti Chakraborty, lead author of the study and researcher at the BFW. “This would drastically undermine the role of European forests in mitigating climate change.”
Study Assisted Migration (source BFW)
The solution, according to the study, lies in careful selection of seed sources that are adapted to the climate conditions projected for the planting location, even if these sources originate from geographically distant regions. This strategy, known as “assisted migration,” leverages the genetic diversity within tree species to ensure that the forests of the future can thrive and continue to sequester carbon effectively.
“Our findings demonstrate the remarkable potential of assisted migration to maintain or even enhance the carbon sequestration capacity of European forests in the face of climate change,” says Silvio Schueler, project leader and corresponding author of the study from the BFW. “By strategically choosing seed sources that are adapted to future climate conditions, we can ensure that reforestation efforts effectively contribute to climate change mitigation.”
The study’s findings have profound implications for forest management and conservation policies across Europe.
“This research provides crucial scientific evidence to support the integration of assisted migration into national and transnational forest management strategies, emphasizes Schueler. “To secure the future of our forests and their crucial role in mitigating climate change and providing sustainable wood products we need to implement this knowledge urgently.”
The study has been supported by the INTERREG Central Europe Cooperation SUSTREE (Conservation and sustainable utilization of forest tree diversity in climate change) and Horizon 2020 Project SUPERB (Systemic solutions for upscaling of urgent ecosystem restoration for forest-related biodiversity and ecosystem services), with the latter being coordinated by the European Forest Institute.
Overall, the study confirms the need for further international collaboration in research and development to refine assisted migration strategies and address potential ecological and socio-economic implications. This will ensure that the forests of the future are resilient, diverse, and equipped to cope with the challenges of a changing climate.
Featured image: Calabrian Black Pine (Pinus nigra subsp. laricio), photo by Viktoria Valenta, BFW
