They survived wildfires. But something else is killing Greece’s iconic fir forests | Trees and forests

IIn the southern Peloponnese, the Greek fir is an imposing presence. Slow-growing, deep green conifers have long defined the region’s high-altitude forests, thriving in mountains and rocky soils. For generations, they have been one of the country’s most resilient species, exceptionally able to withstand the drought, insects and wildfires that periodically ravage Mediterranean ecosystems. These Greek forests have lived with fire for as long as anyone can remember.

So when Dimitrios Avtzis, a senior researcher at the Forestry Research Institute (FRI) in Elgo-Dimitra, was sent to document the aftermath of a spring fire in the region, nothing about the mission seemed out of the ordinary. He had traveled countless burned landscapes, tracking the expected pockets of mortality, as well as the trees that had survived their burns.

This time, however, something went wrong almost immediately. The scale was out of reach. As Avtzis and his colleagues moved deeper into the trees, the familiar images of a post-fire forest gave way to something far more disturbing.

“There were hundreds and hundreds of acres of trees lost,” he says – not just those lost in the fire itself, but vast patches of dead and dying greenery where the flames hadn’t reached them.

In the Peloponnese mountains, entire tracts of green forest turn orange as long-lived fir trees dry up and die. The level of destruction was so much higher than what Avtzis had seen in previous years that it forced him to immediately contact the Ministry of the Environment and sound the alarm.

“The extent of the damage was considerable,” he said.

Researchers across Greece and central Europe have been warning for years that climate breakdown will push local ecosystems into uncharted territories. Wildfires are not new: according to data from Global Forest Watch, between 2001 and 2024, Greece lost 200,000 hectares (500,000 acres) of trees to fires.

But it’s not just fires that kill trees, and the forces that determine the outcomes of wildfires have changed dramatically over the past five years. What Avtzis saw was the result of multiple overlapping pressures, each amplified by the climate crisis.

The first is severe and prolonged drought, which is now a defining feature of Greece’s climate. The drought is made worse by a steady decrease in winter snow. A study by the Institute for Environmental Research and Sustainable Development and the National Observatory of Athens found that between 1991 and 2020, Greece lost an average of 1.5 days of snow per year, eroding one of the country’s most important sources of slow-release moisture.

Then comes the biological consequences. Soils degraded by drought and reduced groundwater weaken fir trees, creating an opening for insects. “We know that severe drought weakens trees,” says Avtzis. “But when we looked more closely at what was happening, we found that the bark beetles had taken advantage of it. They were attacking the trees.”

Bark beetles – particularly those in the subfamily Scolytinae – have become a growing threat to Greece’s already threatened forests over the past two years.

Their name comes from the fact that the insects burrow beneath the outer bark, severing the systems that trees rely on to transport water and nutrients. Once they establish themselves inside drought-prone fir trees, their numbers can increase rapidly. “When a population reaches epidemic levels,” Avtzis explains, “it becomes extremely difficult to bring it back under control.”

The phenomenon is not limited to Greece. Bark beetle outbreaks have become a broader concern in Europe, Avtzis says, mirroring trends seen elsewhere on the continent. “Southern Europe may be more vulnerable,” he says, “but we see a similar dynamic in countries like Spain. »

The implication is worrying – indicating that the causes of the disappearance of the Peloponnese are not local anomalies, but symptoms of a broader ecological change.

Yet amid the growing pressures of the climate crisis, cautious notes of optimism are emerging. Nikos Markos, forest climatologist at FRI, highlights the regenerative capacity of Mediterranean ecosystems. “Regeneration after a fire can be quite satisfactory,” he says, “even in some areas of the Peloponnese.”

However, the recovery is slow and uneven. “It’s not something we can see in the first year,” Markos adds. “It may take four or five years.”

Avtzis is pragmatic when he talks about what it will take to protect the forests of the Greek highlands. “I’m going to be realistic,” he said. “The government and ministries must take the initiative and mobilize the necessary funding to tackle this problem. »

Some steps, he notes, were already underway by the time he submitted his report on the Peloponnese. “They contacted the major regional forestry services and asked them how much funding was needed,” he says. “What really matters now is whether these plans are actually implemented. »

When asked whether weather changes in Greece are likely to continue to accelerate and whether this poses an existential risk to southern Europe’s forests, Avtzis pauses. “There is no time to be pessimistic,” he said. “But we have a lot of work to do.”

The tools, he says, already exist. “We have the knowledge. We have the scientists. Now we need to start talking about it,” he says. “Because what we see now will only become more frequent and more intense.”

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