Author: Tom Locatelli, Forest Research
For the past 75 years, windstorms have been the primary natural disturbance affecting European forests, resulting in massive timber losses. Notable events include the 1990 Vivian and Wiebke storms causing around 100 million cubic meters (Mm³) of timber damage across Central Europe; the record-breaking 1999 Lothar and Martin storms with nearly 240 Mm³ lost mostly in France and Germany; and the 2005 Gudrun storm, which resulted in approximately 75 Mm³ damage, particularly in Sweden – equivalent to one year’s harvest. Storm Kyrill and Per in 2007 affected a dozen countries with combined losses close to 66 Mm³; storm Klaus (2009) caused damage exceeding 40 Mm³, primarily in southern France’s Aquitaine region. A rare summer windstorm in 2017 led to over 8 Mm³ of losses in Poland, while the 2018 storms Friederike and Vaia had damage volumes of roughly 17 Mm³ in Germany and 12 Mm³ in Italy, respectively. More recently, storm Éowyn in January 2025 inflicted timber losses in Ireland surpassing the country’s mean annual harvest.
Beyond timber loss, windstorms also affect forest carbon stocks including emissions from disturbed soils, contributing significantly to carbon losses (Lindroth et al., 2009). Windstorms impair local economies dependent on forest ecosystem services, impacting cultural and recreational activities. Treefall from storms disrupts transport and infrastructure, leading to road closures and loss of power and telecommunications, affecting local communities (Gardiner et al., 2013).
Economic Impacts
The economic losses from windstorms are intricately tied to the scale and severity of forest damage. Major European windstorms have caused wide-ranging disruptions, notably flooding national and international timber markets with salvaged timber. Such market saturation causes timber prices to collapse, a consequence felt long after the event as harvesting in unaffected areas is delayed to protect timber value (Udali et al., 2021). Economic losses encompass not only lowered timber value but also the considerable costs of salvage logging, forest access restoration, and restoration of utility services.
Insurance and reinsurance sectors face significant strain during severe storms, necessitating sometimes public financial support. For example, forestry sector losses from the 1990 storms are estimated around €4–6 billion; the 1999 storms’ timber damage was valued at about €7 billion, and the 2009 storms at roughly €2 billion. Kyrill resulted in insured losses over €2 billion, and Friederike caused about €1.6 billion in insured losses in Germany alone.
Biodiversity Implications
Severe windstorms profoundly alter forest ecosystems by uprooting and damaging entire tree stands, causing sharp biodiversity declines. Post-storm ecosystem trajectories depend largely on management choices. Salvage logging aims to recover timber and prevent pest outbreaks, often creating a "blank slate" for succession or alternative land use. Conversely, minimal intervention allows natural regeneration, which can promote structural diversity and ecological resilience (Sanginés de Cárcer et al., 2021).
Tree Adaptations and Damage Mechanics
Trees have evolved adaptive strategies to endure wind stress, with conifers and broadleaves displaying both shared and distinct traits related to crown architecture (Jackson et al., 2020) and root development (Nicoll et al., 2008). Damage manifests mainly as branch or foliage loss, stem breakage, or uprooting. Studies combining lab tests, field observations, and modelling have helped create wind risk decision support tools (DSTs) such as HWIND (Peltola et al. 1999) and ForestGALES (Locatelli et al., 2022), widely used in Europe to inform forest management.
Climate change is expected to exacerbate storm risks by encouraging faster tree growth, which can reduce structural stability, while also increasing the frequency and intensity of extreme wind events (Seidl et al., 2014). Although average wind speeds may remain stable or decline slightly, extreme events are projected to become more intense and frequent, with changing seasonality resulting in more summer storms when broadleaved trees are more vulnerable due to leaf presence. Forest managers’ attitudes towards wind risk are influenced by recent storm losses and availability of financial incentives for mitigation (Brunette and Couture, 2008).
Knowledge Gaps
While modern close-to-nature forest management is thought to reduce vulnerability, much of this rests on anecdotal evidence. Ongoing research in Europe is investigating the complex interactions of species composition and stand structure on wind damage risk (e.g. in the UK). There is limited understanding of compound risks involving windstorms combined with other disturbances such as drought or soil waterlogging, which impair tree stability.
The divergence between trends in mean wind speeds and extremes adds uncertainty to projections of forest resilience. Recently, scientific focus has increased on how wind affects tree growth, timber properties, and carbon stocks – key knowledge gaps relevant to both policy and practice (Dlouhá et al., 2025). Improved integration of environmental, social, and cultural dimensions of wind risk would enhance forest resilience policy development across European scales (Romagnoli et al., 2023).
Management Strategies to Reduce Wind Damage
Effective forest management to mitigate wind damage depends on forest type, geographic location, landscape context, soil conditions, tree age, and management objectives. Generally, creation of new forest edges should be minimized to avoid unacclimated trees exposed to harsher wind climates.
If thinning is necessary, it should be performed early to promote stable tree taper and root development. Increasing structural diversity through species mixtures and uneven-aged stands promotes greater stability, although care is needed since a high proportion of deciduous species could increase wind penetration in winter storms, exposing evergreen trees in the mixture to higher wind loads (Gardiner et al., 2024).
DSTs can assist managers by predicting when stands become vulnerable, promoting timely management actions that prevent damage. These tools incorporate local wind climate, forest composition, and stand metrics, thereby empowering forest managers and planners to take present action to prevent future damage.
References
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