Focal Area

Windstorms

Windstorms are among the most destructive natural disturbances affecting pan-European forests.

While traditionally considered rare and localized, their frequency and intensity are increasing due to climate change, posing a growing threat across the continent. From the Atlantic coast to Central Europe, forests are being exposed to stronger and more erratic storm events, often with little warning.

Challenges in Managing Windstorm Disturbances

Despite their impact, windstorms present a unique challenge: they occur infrequently in any one region, making it difficult to maintain readiness. Forestry personnel and landowners often lack hands-on experience, and training for such rare events is hard to sustain. When storms do strike, the damage can be severe, such as disrupted ecosystems, economic and human loss and cascading effects arise like increased vulnerability to pests and fire.

The unpredictability of extreme weather events demands adaptive strategies, yet many countries still rely on traditional plans that don’t account for rapid change.

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Christoph Hartebrodt

Expert insight

Christoph Hartebrodt

Christoph Hartebrodt, a forestry expert with nearly 40 years of experience, has long focused on storm damage and crisis management. His work spans both technical forestry and institutional resilience, shaped by events like storm Lothar which struck western Europe in 1999, along with bark beetle outbreaks effecting native German forests.

“Fortunately, severe storms are still a rare event in a single region,” he notes. “But this rarity always leads to the problem of lacking specific experience… knowledge that cannot be applied promptly is quickly forgotten.”

Forestry’s tradition of long-term planning is increasingly challenged by the pace and unpredictability of climate-related disturbances. Christoph emphasizes that resilience now requires flexible management approaches capable of responding to shifting patterns and intensities. Strengthening adaptive capacity involves continuous learning, targeted training, and improved coordination across sectors.

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FoRISK’s Role in Strengthening Windstorm Resilience

Managing windstorm risks in pan-European forests requires a shift toward more adaptive strategies and expertise exchanges. While natural hazards like windstorms cannot be prevented, their impacts on forest systems can be mitigated through strategic planning and enhancing resilience. FoRISK is actively addressing these challenges by connecting forest professionals, supporting knowledge exchange, and promoting preparedness in regions newly exposed to windstorm disturbances.

FoRISK is actively addressing these challenges by connecting forest professionals, supporting knowledge exchange, and promoting preparedness in regions newly exposed to windstorm disturbances. An example of FoRISK work is its collaboration with the Irish Ministry of Agriculture, which amplifies this approach, supporting the development of a dynamic wind-blow strategy and facilitating targeted workshops to build local capacity.

Through its expert network and knowledge-sharing activities, FoRISK helps forest professionals across pan-Europe respond effectively to windstorm disturbances, while also strengthening resilience to other natural threats such as wildfires and biotic agents.

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Key actions supported by FoRISK include:

Expert exchange and crisis management training:

Facilitating collaboration among forest disturbance experts and providing rapid support when windstorms occur.

Capacity building in affected regions:

Offering tailored workshops and training programs to strengthen institutional readiness and response capabilities.

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Practical resources via the FoRISK Intelligence Hub:

Delivering accessible, science-based tools and guidance to support planning, recovery, and long-term resilience.

Windstorms can significantly intensify wildfires through several mechanisms:

  • Access Barriers and Response Delay: Severe windstorms can block roads and damage infrastructure, delaying firefighting response times. Fallen trees and debris can hinder access to fire-prone areas, allowing fires to grow unchecked in the critical early stages.
  • Deadwood and Stressed Trees: Windstorms can dramatically increase the amount of deadwood and physically stressed trees in forested areas. While deadwood plays an important ecological role by enriching soils, supporting biodiversity, and contributing to nutrient cycling. It’s contribution to wildfire risk depends on type, condition, location, and timing. Certain forms of deadwood (e.g. dry, fine fuels in dense clusters) can act as ignition sources and accelerate fire spread, whereas others may have limited flammability or even buffer fire movement. Careful assessment is needed to determine whether deadwood increases or mitigates fire risk in each context[1].
  • Wind-Driven Fire Spread: Strong winds play a critical role in wildfire behaviour by feeding fires with oxygen, accelerating combustion, and transporting embers across long distances. These embers can ignite new spot fires far from the original blaze, leading to rapid expansion and highly unpredictable fire dynamics that challenge containment efforts[2].
  • Canopy Disruption: Windstorms often tear apart forest canopies, exposing the understory to direct sunlight and drying out vegetation more rapidly. This reduction in moisture content makes the forest floor more susceptible to ignition and allows fires to spread more easily through lower vegetation layers[3].

[1] How deadfall from windstorms can affect wildfire behaviour

[2] What causes the powerful winds that fuel dust storms, wildfires and blizzards? | Texas A&M University College of Arts and Sciences

[3] Interactions between wind and fire disturbance in forests_ Competing amplifying and buffering effects

Windstorms

Intersectional windstorms

Windstorms and biotic agents (such as insect pests and pathogens) interact in complex ways that can significantly influence forest health and disturbance dynamic:

  • Windthrow as Breeding Habitat for Pests: Windstorms often uproot or snap trees, leaving behind weakened or dead wood. This creates ideal breeding conditions for bark beetles and other wood-boring insects, which prefer freshly downed trees for colonisation. These populations can then spread to healthy trees, triggering outbreaks[1].
  • Tree Vulnerability from Biotic Damage: Trees weakened by pathogens or insect infestations (e.g. root rot fungi or bark beetles) are structurally compromised and more likely to suffer windthrow during storms. This increases the extent of storm damage and contributes to cascading forest disturbances[2].
  • Facilitated Pathogen Spread: Windstorms can break branches, strip bark, and expose roots, creating entry points for pathogens. These injuries, combined with stress from mechanical damage, make trees more susceptible to infection and disease spread[3].

[1] Climate change amplifies the interactions between wind and bark beetle disturbances in forest landscapes.

[2] Climate change amplifies the interactions between wind and bark beetle disturbances in forest landscapes

[3] Storms, wind throws and their consequences

Wildfires

Intersectional windstorms

Windstorms can significantly intensify wildfires through several mechanisms:

  • Deadfall: the accumulation of fallen trees, branches, and other vegetation. While deadfall plays an important ecological role by enriching forest soils and providing habitat, windstorms can dramatically increase its volume. This excess debris becomes highly flammable, acting as ideal fuel and ignition material for wildfires, thereby accelerating their spread and intensity[1].
  • Wind-Driven Fire Spread: Strong winds play a critical role in wildfire behaviour by feeding fires with oxygen, accelerating combustion, and transporting embers across long distances. These embers can ignite new spot fires far from the original blaze, leading to rapid expansion and highly unpredictable fire dynamics that challenge containment efforts[2].
  • Canopy Disruption: Windstorms often tear apart forest canopies, exposing the understory to direct sunlight and drying out vegetation more rapidly. This reduction in moisture content makes the forest floor more susceptible to ignition and allows fires to spread more easily through lower vegetation layers[3].
  • Access Barriers and Response Delay: Severe windstorms can block roads and damage infrastructure, delaying firefighting response times. Fallen trees and debris can hinder access to fire-prone areas, allowing fires to grow unchecked in the critical early stages.

[1] How deadfall from windstorms can affect wildfire behaviour

[2] What causes the powerful winds that fuel dust storms, wildfires and blizzards? | Texas A&M University College of Arts and Sciences

[3] Interactions between wind and fire disturbance in forests_ Competing amplifying and buffering effects

Windstorms and biotic agents (such as insect pests and pathogens) interact in complex ways that can significantly influence forest health and disturbance dynamic::

  • Windthrow as Breeding Habitat for Pests: Windstorms often uproot or snap trees, leaving behind weakened or dead wood. This creates ideal breeding conditions for bark beetles and other wood-boring insects, which prefer freshly downed trees for colonization. These populations can then spread to healthy trees, triggering outbreaks[1].
  • Fuel Load Amplification:
    Insect outbreaks such as bark beetles and defoliators can cause widespread tree mortality, leaving behind large quantities of dry, dead biomass. This deadwood increases surface and canopy fuel loads, making forests more prone to intense and fast-spreading wildfires. The timing and severity of outbreaks play a critical role in determining whether they amplify or dampen fire behavior[1].
  • Tree Vulnerability from Biotic Damage: Trees weakened by pathogens or insect infestations (e.g. root rot fungi or bark beetles) are structurally compromised and more likely to suffer windthrow during storms. This increases the extent of storm damage and contributes to cascading forest disturbances [2].
  • Facilitated Pathogen Spread: Windstorms can break branches, strip bark, and expose roots, creating entry points for pathogens. These injuries, combined with stress from mechanical damage, make trees more susceptible to infection and disease spread [3].

[1] Climate change amplifies the interactions between wind and bark beetle disturbances in forest landscapes.

[2] Climate change amplifies the interactions between wind and bark beetle disturbances in forest landscapes

[3] Storms, wind throws and their consequences