Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.

To compare the provision of ecosystem services in plantation forests under alternative climate change adaptation management trajectories, we interpolated climatic variables from the UK 11-member regional climate models to use at high resolution in forest management situations. We used expert opinion to derive the links between coarse-scaled UK National Ecosystem Assessment scenarios and forest management alternatives (FMA) in a simulation of forest planning and management under climate change uncertainty. Nine indicators were used to compare the provision of forest ecosystem services from four alternative management trajectories based on FMA types under a changing climate. These show that by 2080 a 'business as usual' form of forest management at both Clocaenog and Gwydyr forests will become unsuitable under the two warmest and driest climate variants, marginal under four variants, and borderline suitable under the remaining five variants. This implies that if future forest policy requires the continued delivery of a wide range of ecosystem services, including, home grown timber, biodiversity, and the carbon mitigation benefit from woodlands, then there is 20-50 % chance of failing to deliver on some of these services, unless some adaptation measures to climatic impacts occurs, such as transformation to more diverse species forests managed using low-impact silviculture systems. We show that the benefits of achieving this will be to minimise most of the impacts that climate change would otherwise have on the delivery of ecosystem services from forests.

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Adapting forests to climate change involves silvicultural measures such as use of a range of species and the fostering of mixed stands. We tested these in a Sitka spruce forest in southern Scotland, employing the Ecological Site Classification to match suitability of 24 species to six climatic and edaphic variables under values of accumulated temperature and moisture deficit projected for a medium emissions scenario for the present century. Both median and 90 th percentile values were contrasted. In the first case there was a small change in species suitability with Sitka spruce, noble fir, downy birch, sycamore and aspen being the most suitable species. When the 90 th percentile values were employed, the suitability of Sitka spruce and similar conifers had declined by the 2050's due to soil moisture deficits. The actual performance of a range of species in a long-term experiment on a similar, warmer site showed several productive conifers including Sitka spruce that maintained reasonable growth when planted in mixture. Mixed plots were developing into pure stands of the most productive species. Species diversification was the most practical adaptation measure for this forest and should concentrate on areas of the greatest risk like south-facing slopes with free-draining soils.