New policy brief on increased forest disturbances

Based on their recently published paper, RESONATE researchers Marco Patacca (Wageningen Research), Marcus Lindner (RESONATE Coordinator, EFI) and Gert-Jan Nabuurs (Wageningen Research) together with European Forest Institute’s Policy Support Facility and Mart-Jan Schelhaas (Wageningen Research) developed this policy brief, reporting significant increase in forest disturbances since 1950s. The policy brief also refers to a second paper published by RESONATE researchers and explains key trends:

  • Wind disturbances caused 46% of total timber volume damage. The majority were extreme windstorms (peaks),
    supplemented by widespread chronic damage with particularly high rates in the 1990s and 2000s.
  • Forest fires were responsible for 24% of total timber volume damage. In the 1970s and 1980s, there was a
    significant increase in fire disturbance, followed by two opposing trends. Smaller and average-sized fires have
    decreased since the late 1990s as a result of improved fire management, detection and control, but climate
    change related mega-fires increased. Most recent research predicts that fire size and severity will increase across
    all European biomes under future climate conditions.
  • Almost 20% of damage was caused by bark beetle calamities with a dramatic increasing trend in the last decade.
    The years 2020 and 2021, which had even greater damage, were excluded.
  • Pests and diseases (other biotic damages) accounted for 8% of total timber damage with the strongest positive
    trend and a sharp increase after the 1980s, most likely influenced by climate change.
  • Other abiotic disturbances (e.g. due to snow and ice) increased, with certain years (e.g.2007) exhibiting high
    damage peaks.

The brief reports that data analysis revealed that consistent data collection on disturbance events is lacking, particularly for the reporting of smaller, dispersed damage. Finally, the authors share their recommendations on what to improve:

  • A harmonized, consistent and near-real-time pan-European monitoring and reporting system of forest disturbances is needed, with improved data collection on small disturbance impacts.
  • A combination of ground-based observations and remote sensing is necessary for a consistent monitoring and reporting system.
  • Special efforts are required to better understand disturbance dynamics, especially the expected increase of drought and biotic agents, as well as disturbance interactions.

More information

Download the policy brief:

Patacca, M., Lindner, M., Nabuurs, G.-J. and Schelhaas, M.-J. 2023. Significant increase in forest disturbances since 1950s. Policy Brief 4. European Forest Institute.