Remove the small wood and keep the big one
Dead wood in forests serves as shelter for life, a hiding place, and food for fungi, insects, and many other creatures. The new EU Nature Restoration Law aims to boost the amount of this material to monitor and restore biodiversity. Yet some groups warn that dead wood can pose a fire risk and should be cleared when necessary. The question remains: how should forest managers handle dead wood that results from drought, pests, or wind events?
In this regard, a new European project called BioAgora has been launched. The Center for Ecological Studies and Forestry Practices, CREAF, is a major partner and has activated the Biodiversity Scientific Service. This service helps the scientific community quickly assemble available information on the topic and advise European decision makers.
The resulting synthesis report, Deadwood and Fire Risk in Europe, concludes that large amounts of dead wood in European forests do not significantly raise fire risk, while they play a crucial role in maintaining biodiversity.
It is a low combustible wood that does not necessarily increase wildfire risk
The study indicates that dead wood can contribute some fuel during wildfires, yet its combustion varies with wood type. In the Mediterranean, forests tend to contain little dead wood of substantial size, so fire risk is not primarily driven by dead wood and biodiversity goals should guide management to healthier, more resilient forests. In some cases, thicker logs can even help retain soil moisture and impede the spread of surface fires.
Manage structure: prioritize large, biodiversity-rich pieces
In droughts or pest outbreaks that raise dead wood levels, the option to remove finer, highly flammable material will be weighed against retaining the largest pieces that support biodiversity and pose lower fire risk. CREAF researcher Josep Maria Espelta explains that the emphasis should be on preserving thick, slow-burning dead wood while reducing fine fuel that accelerates spread.
Collaborating with the Catalonia Forest Science and Technology Center, CREAF and CTFC distinguish dead wood that is thick and low in combustibility as essential for forest health. Fine twigs that contribute little to biodiversity may play a larger role in ignition and spread of fires.
Recover natural processes such as fire
The report offers scenario-based recommendations. In zones with high fire risk, specialized forest management can prevent fire spread while supporting natural processes such as controlled, low-intensity fires moving those processes forward in a safe direction.
Small, controlled fires can effectively reduce risk while protecting biodiversity. These burnings help reduce fuel loads, particularly fine woody residues, and create firebreaks that interrupt forest continuity.
As Lluís Brotons, a CREAF and CSIC researcher, notes, the careful use of fire can foster diverse habitats over time. Fire acts as a catalyst for ecological variety, contributing to resilience against large wildfires when applied under appropriate conditions.
New disturbances call for thoughtful protection of forest health
When large areas suffer from disturbances such as wind storms, pests, or heavy snowfall, strategic public use or response is necessary to lower fire risk. The study acknowledges the need for careful judgment in such scenarios, balancing safety with forest health goals.
Mediterranean forests as a model of resilience
The Mediterranean basin faces nutrient-poor soils and frequent droughts. There is broad scientific consensus that keeping some dead wood in these forests helps maintain health and resilience to climate change. Dead wood supports many species and helps retain soil moisture, aiding life in a drying climate.
Dead wood as habitat and soil moisture
The Mediterranean forest is highly prone to fire risk and carries a long history of intensive management, leaving little large dead wood today. The greatest risk arises from increased continuity of forest mass when management declines. A shift in pest pressure, drought, or storms can temporarily raise dead wood levels, in which case selective removal of the thinnest pieces may be considered, according to Espelta.
In summary, the report highlights the need to balance dead wood management with fire risk and biodiversity goals, ensuring forests remain healthy and resilient in a changing climate.
Endnotes reflect ongoing research from CREAF and CTFC researchers, focusing on the ecology of dead wood, fire risk, and forest resilience across Europe. These insights inform forest managers and policymakers as they navigate biodiversity objectives alongside safety considerations.