Increasing forest disturbances in Europe and their impact on carbon storage.

Disturbances from wind, bark beetles, and wildfires have increased in Europe's forests throughout the 20th century 1. Climatic changes were identified as a main driver behind this increase 2, yet how the expected continuation of climate change will affect Europe's forest disturbance regime remains unresolved. Increasing disturbances could strongly impact the forest carbon budget 3,4, and are hypothesized to contribute to the recently observed carbon sink saturation in Europe's forests 5. Here we show that forest disturbance damage in Europe has continued to increase in the first decade of the 21st century. Based on an ensemble of climate change scenarios we find that damage from wind, bark beetles, and forest fires is likely to increase further in coming decades, and estimate the rate of increase to +0.91·106 m3 of timber per year until 2030. We show that this intensification can offset the effect of management strategies aiming to increase the forest carbon sink, and calculate the disturbance-related reduction of the carbon storage potential in Europe's forests to be 503.4 Tg C in 2021-2030. Our results highlight the considerable carbon cycle feedbacks of changing disturbance regimes, and underline that future forest policy and management will require a stronger focus on disturbance risk and resilience.