Madrid is tackling its ‘biggest environmental catastrophe’ in years by cloning trees

After the worst snowstorm in decades damaged half a million of Madrid’s trees, a specialist arboreal rescue team is swooping in to clone some of the most valuable specimens, creating genetically identical copies for future generations to enjoy.

Storm Filomena crashed through central Spain in early January, cutting off transport links to the capital and causing hundreds of millions of euros of damage.

“It’s the biggest environmental catastrophe of recent years,” said Francisco Molina, head of agroforestry at Madrid’s IMIDRA rural development institute. “There’s been an unprecedented loss of natural heritage.”

Pruning saw in hand, he clambers under a 100-year old cork oak in the suburb of Las Rozas, which collapsed under several tonnes of snow. After chopping off a long bough, he painstakingly strips away any smaller twigs and cuts it into regular 20cm sections to be bundled up and sent to the lab.

IMIDRA has been cataloguing and cloning Madrid’s noteworthy trees for 10 years, but after Filomena the agency offered help replacing trees with sentimental value.

So far they have received requests from 30 local authorities to clone more than 100 species, including corks and holm oaks.

Emblematic of the Spanish interior, the evergreen oaks sustain the country’s famed acorn-fed pigs, but their broad leaves make them highly vulnerable to heavy snow.

Complicating the cloning effort, they are incapable of reproducing via a simple transplant, forcing the team to adopt a more complex approach known as somatic embryogenesis - the plant equivalent of in-vitro fertilisation.

The samples are scrubbed with a stiff brush, bathed in fungicide and bleach, then placed in a substrate to encourage fresh leaflets to grow.

“What we are trying to do is to induce acorn seeds to form from these leaves,” said IMIDRA researcher Inmaculada Hernandez.

It will take decades to replace the losses, but Molina believes it is worthwhile to preserve the genes of trees that have withstood a century of climate change, blight and insect attacks.

“When we suffer the tragedy of losing one we come running,” he said.