Science1 publisher3 min readPublished
eLTER presses Europe to put a number on how fast its forests recover
A new policy brief argues Europe's forest reporting counts area and biomass well and regrowth barely at all. It stops short of naming the threshold that would turn a declining satellite signal into a trigger for action.
The Scientist · Science desk
What happened
- A new eLTER policy brief argues that resilience should be an explicit and measurable objective of European forest management, not something judged after a disturbance has already done its damage.
- The rate at which European forests are damaged by drought, storms, wildfire and insect outbreaks has more than doubled over the past three decades.
- Prolonged heat and drought stressed forests across much of Europe this summer, and by late August EU wildfires had burned more than 630,000 hectares, roughly twice the 20-year average for the date.
- Monitoring and reporting still centre on how much forest exists and how much biomass it holds, figures that say little about whether a stand can withstand a shock or regrow after one.
- The brief asks for indicators of recovery capacity, regeneration, structural and functional diversity, landscape connectivity, and the capacity of species to adapt or shift their range.
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Why it matters
- exposure The forest carbon sink is inside European climate arithmetic, so uptake that weakens quietly transfers obligation to sectors that never touch a tree, which is the brief's route from silviculture to climate targets.
- decision Putting quantitative resilience targets into national strategies forces governments to choose an indicator and a baseline before they can choose a number, and that choice determines which forests officially count as failing.
- constraint Satellite early warning shortens the detection lag without settling the judgement call: direction of travel is not the same as a trigger to thin, replant or write off a stand.
- cost Routing the funding through payments for ecosystem services and nature credits makes resilience work depend on someone buying an ecosystem outcome rather than on harvest income covering it.
Halve the burned-area figure and the comparison gets concrete: the 20-year average for the same point in the season sits somewhere near 315,000 hectares [20]. Useful, and still a hazard statistic. Hazard is the part of this that European forest reporting handles; the brief is aimed at the decade after the fire, when the question is whether the stand comes back [3].
"Resilience is not simply whether a forest is still standing after a disturbance," writes Giorgio Vacchiano of the University of Milan, the brief's author; the question is whether forests can maintain their functions, regenerate and adapt, and "if we do not measure those processes, we cannot manage them" [8]. The instrument he points to is satellite observation, where a drop in photosynthetic activity can flag slowing recovery before decline is visible from the ground [13]. The thing that signal does not carry is a number to act on. The brief describes stands approaching a critical threshold without publishing where the threshold sits [13], and an index sliding for one species on one soil is a slope until someone has a local baseline to compare it against. That is the argument for the long-term field observation the brief asks governments to pay for [16].
The carbon figure deserves more care than it usually gets. European forests absorb around 360 million metric tons of carbon dioxide a year, and the brief says that sink is weakening for three reasons at once: stands ageing, harvesting intensifying, and disturbance becoming more frequent [9]. Those trends move together, and the brief does not apportion them. Which one dominates decides the response, because an ageing-stand effect is a legacy of past planting, a harvest effect is a market and regulation question, and only the third is what resilience management directly addresses. The brief's own conclusion is that without adaptation, European climate targets get harder to meet [10].
Compound events are where the measurement gap bites hardest. Drought followed by fire or pest outbreak magnifies losses and slows recovery further [6], and conventional assessment systems represent those sequences poorly [14]. A stand hit twice inside a few years enters the record as two moderate disturbances rather than as one failure to regenerate, which is the distinction the whole brief turns on.
The bill is already being paid. Climate-driven damage costs several billion euros a year [5], and the exposure runs past timber to biodiversity and rural livelihoods, with raised odds of floods and landslides where cover fails [21]. The management menu the brief sets out is broadly familiar: closer-to-nature and climate-smart forestry, more diverse species and structures, restoration of hydrological function, and carefully planned assisted migration [17]. Its five directions for action include writing quantitative resilience targets into national forest, climate, adaptation and nature restoration strategies [16], and it points to fire-prevention planning in Tuscany and Lombardy as regional practice of the kind it wants generalised [19]. Until a repeat inventory cycle reports recovery capacity for a defined forest type, a resilience target in a national strategy has a numerator and no denominator.
What to watch
- Whether any member state writes a resilience indicator into its national forest or nature restoration strategy with an actual numeric target attached.
- The closing EU burned-area total for 2026, and whether it stays near twice the long-term average once the season is fully accounted for.
- Whether the long-term observation and research infrastructure the brief asks governments to fund receives money rather than endorsement.