Vicki Barker for NPR
This 400-year-old beech tree at the Ashridge Estate in southeast England is among those being tallied in a tree census. Experts hope the count will offer clues on how to maintain biodiversity in the transition to the next generation of trees.
This 400-year-old beech tree at the Ashridge Estate in southeast England is among those being tallied in a tree census. Experts hope the count will offer clues on how to maintain biodiversity in the transition to the next generation of trees. Vicki Barker for NPR
In the Chiltern Hills of southeast England, forester Bob Davis strolls through the woodlands. Davis is a big, bearded, gentle man — think Hagrid in the Harry Potter books — but he is dwarfed by the gnarled and twisted giants around him.
We're walking through to probably the biggest tree in the woodland," he says. "It's a bit of a 'wow factor,' this one."
He points to a beech tree believed to be 400 years old. The tree, in a dim, dappled clearing, is almost as wide as it is tall. It has a mossy, twisting, bulbous trunk and water pooling on its pocked bark.
Naturalists say as many as 70 percent of Europe's ancient trees may be in Britain. Now, two British charities are working to identify every single one. The National Trust, Britain's conservation charity, has signed on to a five-year census of ancient trees organized by a sister charity, the Woodland Trust.
Nikki Williams, the project director, says there is more at stake than just the trees.
"They are mini-ecosystems in their own right. If we lose these trees, then Great Britain will also lose a lot of its indigenous species," she says.
An English oak can live 900 years. Britain's most ancient tree, a yew, could be 3,000 years old. They are the last remnants of the forests which once covered all of Europe.
But make reference to "virgin" forests, and naturalists will reply that there has been no such thing here for eons. The earliest Britons were already pruning young trees to harvest timber and fuel about 6,000 years ago, a millennium before Stonehenge was created.
Davis is head forester of the National Trust's 700-year-old Ashridge estate, a job that stretches back to medieval times. He worries that ancient trees like his beloved beech are becoming increasingly isolated.
"There are some sort of insects that only live in the pools that are on trees. And then there are things that live on the things that live in the pools," Davis says, explaining the biodiversity of a single tree.
When it is time for insects to mate, they need a similar habitat nearby. But with the disappearance of old-growth trees, other species are threatened, too. "One of the problems with the modern world is, we've fragmented these habitats," he says.
At Osterley House, another National Trust property — 350 acres of parkland directly under the approach path to London's Heathrow Airport — the same intricate ecological dance goes on.
Brian Muelaner, a transplanted Canadian, says only when every ancient tree has been tallied can scientists determine how best to help them and how to maintain that biodiversity in the transition to the next generation of trees.
"What our survey will indicate is whether we have enough successional planting in place to ensure that we're preparing for that transition," he says.
Foresters say that if the trees are allowed to die isolated, lonely deaths, the myriad creatures that inhabit them could die, too.