LISBON — Before it gained global infamy as the “road of death,” Estrada National 236-1 was a bucolic drive, winding in a succession of lazy curves through the thickly wooded hills of central Portugal.

The surrounding greenery, however, brought no joy to environmentalists who have long warned that Portugal was courting disaster through decades of planting the eucalyptus trees which line that roadside and cover much of the country.

On Saturday, a lightning strike is believed to have ignited vegetation, bone dry after a drought and heat wave that pushed temperatures over 40C. Gusting crosswinds fanned the flames which roared through the forests killing at least 63 people, many trapped in their cars on EN236-1.

As the country united to come to terms with the “unprecedented tragedy” and 3,000 firefighters battled on several fronts to contain the conflagration, President Marcelo de Sousa spoke for the political class Monday when he said it was too early to debate “causes, reflection, analysis” of what might be to blame.

For many, however, it was clear the eucalyptus played a part.

“The eucalyptus is more dangerous than other trees,” said João Branco, president of Quercus, an environmental campaign group.

“The leaves and the bark are very flammable, strips of bark hang off the trunks and are carried by the wind, spreading the flames,” Branco, a forestry engineer, added. “Large parts of the center and north of the country are almost completely covered by eucalyptus and it contributes to this type of fire.”

A native of Australia, the eucalyptus was first introduced in Europe as an ornamental plant in the 18th century. It thrived in Portugal, where the fast-growing species was later used in reforestation and to prevent erosion.

It really took off from the mid-20th century to provide raw material for the paper and paper pulp industry.

Thousands of jobs

Now the Aussie import is Portugal’s most common tree.

It covers over 900,000 hectares, a quarter of total forest land, displacing native oaks, laurels and chestnuts. Forests of the tall, slender tree fill up vast tracts of the country, from the hills around the site of this week’s disaster to lowland forests stretching southeast from Porto.

Aside from the fire hazard, conservationists say the eucalyptus sucks up scarce ground water, wipes out competing native species and destroys habitat for native animal life.

For decades, efforts to contain its growth ran into opposition from Portugal’s powerful paper industry lobby.

“Restricting the most important raw material of the paper industry would dramatically affect its competiveness and the country’s trade balance,” the industry body CELPA warned in response to government proposals to ban new eucalyptus plantations. “The ban would destroy thousands of forestry jobs, many in badly depressed regions.”

The industry’s concerns carry weight. From high-quality printing sheets to trendy black toilet rolls, paper exports are big for Portugal.

Last year pulp and paper accounted for 4.9 percent of all exports, worth around €3 billion. The industry employs around 3,000 people, often in rural areas.

Industry association CELPA officials sid much of the criticism directed against the eucalyptus was based on “myths.”

“More important than ‘attacking’ a species … it’s essential to ensure a good management of the bush and the forests and the spaces around them to significantly strengthen prevention,” CELPA said in a statement sent to POLITICO.

The industry association dismissed claims that cutting back the eucalyptus would reduce Portugal’s wildfire risk as “erroneous and prejudiced.”

Banning new plantings will lead to more rural land being abandoned, increasing the risk of fires, it said, stating that uncultivated land represented 49 percent of territory burned in the past 15 years.

On its website, however, the industry recognizes that much of the eucalyptus forest — most of which is on private land, much of it run by small-scale producers — suffers from “insufficient levels of management, poorly adjusted density, aging and bad health” that leave it at risk from fire, pests and disease.

“It’s become vital to promote good practice in forest management generally, and particularly for the eucalyptus,” CELPA said when it launched a “Better Eucalyptus” awareness campaign in 2015.

'Firefighter trees'

Environmentalists agree on the importance of reversing rural depopulation and improved forest management to help reduce the bushfire risk.

However, they say, measures such as mandatory clearing of dead material from the undergrowth, wider firebreaks, or safety zones along highways and around homes must be combined with restrictions on eucalyptus.

Campaigners want “species substitution” and the planting of barriers of native species to serve as “firefighter trees” that are more resistant to fire -- oak and chestnut are reputedly very effective. Most of all, they want the Socialist government to push through its proposal to limit further expansion of the eucalyptus forest.

The cabinet sent the bill to parliament in April, but Quercus and other campaign groups complain of feet dragging under pressure from the paper industry.

Luís Capoulas Santos, Portugal's minister for agriculture, forestry and rural development, says the government wants to prohibit any expansion of the eucalyptus, but his priority is to improve forest management.

“The fire risk is raised most of all by failure to clean up the forest, resulting in an excess of flammable material and hindering access for firefighters,” his office said a written reply to questions from POLITICO. “It is the government's objective to halt expansion of the area planted with eucalyptus plantation area,” he added. “This area has reached its maximum limit.”

After this week’s disaster, pressure to move ahead will grow.

“We’ve allowed an uncontrolled invasion of eucalyptus. Even in inaccessible highlands, huge areas are occupied by a monoculture of eucalyptus that’s an ideal fuel for forest fires,” Vital Moreira, a veteran Socialist politician, wrote in his blog.

“It’s not enough to cry for the dead ... We have once and for all to deal with this powder keg represented by the forest we chose to have,” he wrote. “We have to recognize that we’ve created a killer forest.”

This story was updated with a response from Portugal's agriculture and forestry minister, and with a response from the industry association CELPA.