Adapting choice of species and seed origin to enhance and preserve European forest carbon sink

Stockholm

2024

370

Bandaufführung

40005293

The role of European forests as carbon sinks is increasingly endangered by climate change-induced droughts and disturbance events. On the policy level, European Union has an ambitious plan to increase the terrestrial carbon sink and achieve net zero emissions by 2050. Adaptive management strategies such as choice of species and planting materials are therefore crucial for maintaining forest carbon sinks and increasing forest resilience. Assisted migration (AM) of forest tree species and populations was suggested to avoid maladaptation and to maintain forest growth under future climate. We identified AM schemes for seven major European tree species based on 587 range-wide provenance trials, evaluating more than 3000 provenances. Using models that account for environmental and genetic factors of phenotypic trait variations, we estimated the annual aboveground carbon sink (CS) of 40-year-old trees under current and projected future climate by adapting species composition and seed sources. To increase forest resilience under climate change, coniferous trees might need to be replaced by deciduous trees in large parts of their distribution, with significant consequences for ecosystem services and biodiversity. If local seed provenances are employed, this change will result in a decrease of the current CS of 44 Tgyr-1 by 32-43% until 2061-80. However, if seed provenances adapted to the future climate are utilized, current CS can be maintained or even increased to 46-55 Tgyr-1. Transnational AM can boost both resilience and the CS of European forests.