Saving the chestnut: be as patient as possible and not afraid of heights

Status: 04/25/2023 07:26 a.m

The sweet chestnut shaped the forests of north-eastern America for a long time. Then a fungus destroyed a large part of the population. Researchers are now trying to save the tree from extinction. But it’s not just a matter of patience.

By Katrin Brand, ARD Studio Washington

Out of the truck, in the truck, gate open, gate shut: Vasiliy Lakoba has a lot to do on this sunny spring day while his heavy vehicle rumbles through the research farm in Meadowview. Valuable plants stand behind sturdy fences, which should not be nibbled on by deer.

Lakoba – cap, full beard, work clothes – is the research director of the American Chestnut Foundation, a foundation that tries to save the American chestnut here in southwest Virginia.

“It used to be a really big tree that dominated the forests of Northeast America,” says Vasiliy, “with a large canopy, thick straight trunks that yielded good wood, and very prickly fruits that usually contained three nutritious seeds. The chestnuts Gathering and delivering to the towns was an important economic factor in the Appalachia.”

Chestnuts contain many vitamins and minerals – that’s what makes them so nutritious.

Image: Katrin Brand

Saved by the root system

That changed when the Asian bark fungus – probably from Japan – was introduced in 1904. It quickly attacked and destroyed billions of trees. The chestnut has not died out because the root system of the trees remained intact.

But whenever a young trunk grows tall, the fungus attacks. Large ulcers, like open wounds: This is how the disease can be recognized.

If the Asian bark fungus attacks the chestnut, it must be felled quickly so that the aggressive fungus does not spread further.

Image: Katrin Brand

Breed and crossbreed

The Chestnut Foundation has been trying to breed fungus-resistant chestnuts in Virginia since the 1980s. Vasiliy points to a tree with a slender, smooth trunk. It is the descendant of two large surviving chestnuts, which – for whatever reason – survived the attack of the fungus well.

The offspring also appear healthy, although the fungus has already attacked in two places. The strategy of crossing the American chestnut with the Chinese chestnut also promises success. While the Chinese tree looks very different, it is immune to the fungus.

Use at dizzy heights

Either way: Crossing trees is a tedious job, and you should also be free from giddiness. “You have to find a female flower and when it starts developing, cover it with a bag,” says Eric Jenkins, arborist at the foundation.

Then you have to hand pollinate them at the right time, cover again and wait – until October and then harvest the seeds.

Third possibility: genetic engineering. At the State University of New York, a wheat gene is implanted in the genome of the chestnut, which significantly increases resistance.

A matter of many years

There are countless chestnuts of different ages and appearances on the huge site in Meadowview. Decades will pass before it is clear which tree is really resistant. Saving chestnuts therefore requires a great deal of patience and optimism.

And Vasily has it. He genuinely believes it’s only a matter of time before there are trees that resist the disease. But how they can then be brought back into the forests is the next step, and that will take decades to come.

It used to be that a squirrel could reportedly hop from chestnut to chestnut all along the US East Coast without ever having to set foot on the ground. But it will probably never be like that again.

With Patience Against Dying – How the American Sweet Chestnut is Saved

Katrin Brand, ARD Washington, April 24, 2023 8:49 a.m

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