Portugal, Greece, Spain, Chile, California and now Hawaii have all battled wildfires this year as high temperatures and strong winds have whipped small sparks into violent infernos.
But fire needs fuel, and what these places also have in common is an invasive species — Australia’s eucalyptus tree.
It comes from the oldest continent in the world and it can grow in even the driest of places.
For more than 200 years, seeds of the eucalyptus tree have been planted beyond the bounds of Australia’s coastline.
It has been cultivated around the world, making a new home in southern Europe, South America, parts of Africa, the west coast of the United States, and even parts of South-East Asia.
But there is now a debate over whether this tree has been worth the industry and habitat it provides.
Eucalyptus trees mature fast. And in Portugal, as they grew, so too did a lucrative paper industry.
In Chile, rapidly expanding plantations of introduced eucalyptus and pine species feed a $9 billion forestry industry.
In California, the Tasmanian blue gum has become a shady home to birdlife, treasured by some communities, but feared by others.
Because the eucalyptus tree loves fire and fire loves it.
And now, as temperatures across the globe increase and the Earth’s relationship with fire continues to distort, there are places where Australia’s eucalyptus tree has become a problem.
In the early 1800s, the eucalyptus tree was an exotic specimen from the new southern land, and aristocrats, collectors and botanists alike were eager to plant them in gardens around London and Paris.
The seeds grew at a surprising rate.
The Gardeners Magazine published a “notice of remarkable trees” in 1835, describing how several eucalypts had “sprung to six feet [1.82 metres] from Tasmanian seed planted in 1834”, according to Professor Robin Doughty in his published article Not a Koala in Sight: Promotion and Spread of Eucalyptus.
As interest in the new remarkable tree grew across Europe, the benefits of it were being spruiked by enterprising botanists who had sailed south to Australia.
“One indefatigable booster was Ferdinand Jacob Heinrich von Mueller,” Doughty wrote.
“This German-born botanist worked steadfastly to establish a reputation for eucalypts.”
Von Mueller was the first director of the Melbourne Botanic Gardens and was encouraging the wholesale export for Australian eucalyptus seeds.
By the mid-1800s, there was wide discussion about the uses for eucalyptus trees, as well as their beauty, according to Doughty, and there was a belief that specimens grown from native seeds were best.
Von Mueller would send visiting botanists home with seeds and mail them to other correspondents in his network, always championing the benefits of the tree as he saw them.
He believed “eucalypts would bring about the reforestation of large parts of the Mediterranean world denuded by over cutting”, Doughty wrote.
“These amazing trees would supply timber, charcoal, fuel, wood and medicines, as well as draw off standing water and purify the atmosphere.”
Von Mueller was the Victorian government botanist for more than 40 years, writing more than 100,000 letters to his network about the flora of Australia.
Through his work, he cultivated an awareness of the eucalyptus and then a global interest in it.
“This collector-scientist orchestrated and sustained the push, bolstering it with scientific authority: he canvassed colleagues and interested individuals, publishers, politicians, and the public in the benefits of this genus,” Doughty wrote.
“The eucalyptus symbolised also the hegemony of colonial administrators, who could reach into outposts thousands of miles away and bring back new plants for public approval.”
