Evaluating the deployment of alternative species in planted conifer forests as a means of adaptation to climate change—case studies in New Zealand and Scotland

International audience& Context A strategy widely proposed for increasing the resil-ience of forests against the impacts of projected climate change is to increase the number of species planted to spread and reduce the risks from a range of biotic and abiotic hazards. & Aims We tested this strategy in two case study areas in planted conifer forests in New Zealand and Scotland. & Methods The performance of the major tree species and an alternative was compared: radiata pine and Eucalyptus fastigata in New Zealand and Sitka spruce and Scots pine in Scotland. The process-based model 3-PG2S was used to simulate the effects of projected climate change at the end of this century, with and without CO 2 fertilisation, upon pro-ductivity and financial returns. The effects of an abiotic hazard and two biotic hazards were considered. & Results Under the current climate, the major species outperform alternatives in nearly all circumstances. However, with climate change, their relative performance alters. In New Zealand, planting of E. fastigata becomes more attractive particularly when various hazards and elevated CO 2 concen-trations are considered. In Scotland, Scots pine becomes more attractive than Sitka spruce at lower interest rates. & Conclusions The major plantation species in both coun-tries are well suited to the current climate, but deployment of alternative species and/or breeds can help to adapt these planted forests to the impacts of climate change