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There is a small hope that unique British races of the species—isolated from continental Europe 8,500 years ago—may prove unusually resistant to the blight.

During the 19th century, as global trade increased exponentially, so did the incidence of tree blights. In the early 20th century, after rich countries instituted biosecurity regimes, the growth rates slowed, and in America, at least until recently, remained fairly linear. But in Europe, around 1960, the infection rate picked up, very likely due to the trade-boosting effect of economic integration. This not only spread diseases around the continent itself. It also made the law-abiding countries of northern Europe, such as Britain, susceptible to the sloppier customs regimes of the continent’s southern fringe.

http://www.economist.com/news/britain/21580459-arboreal-confirmation-britain-european-country-european-problems-unquiet-woods?fsrc=rss|btn

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A seven-acre section of woodland near Bickleigh belonging to farmer John Greenslade has been decimated by the disease, and a major programme to uproot and destroy affected trees is under way.

Mr Greenslade began planting Byway Woods 20 years ago and has won awards for it.

Thousands of mature, native ash trees are being dug up and burned after the devastating disease ash dieback was confirmed in Devon.

About 2,000 trees at Byway Farm near Tiverton are affected, according to the Forestry Commission.

This is the first confirmed case of the disease in mature, native trees in the region – another nine cases have been confirmed in young trees that have been recently planted at sites across Devon and Cornwall, including two sites on Dartmoor National Park, according to Forestry Commission figures.

Ben Jones, of the commission’s England plant protection team, said: “It appears that the affected trees had the disease when they were planted in 1996-97. It is concerning and we are continuing our investigations into how the spread had taken place and how far it has spread.”

http://www.westernmorningnews.co.uk/Trees-burned-infection-ash-dieback/story-19481835-detail/story.html

Some scientists say the fungus now ravaging trees across Europe is the same as a native species from Japan.

However, the Asian version of the fungus seems to cause no harm to the local Manchurian ash trees there.

Researchers speaking to the Radio 4 programme The Tree Scientists described the misidentification of the fungus.

Joan Webber, principal pathologist at the Forestry Commission, told the programme: “Scientists working together in Japan and Germany have been looking at a fungus associated with native ash trees in Japan. And what they’ve found is that this fungus appears to be the same one causing ash dieback in Europe and now in Britain.”

“Currently when it infects a nursery for instance, it kills all of the saplings, by killing its host it ultimately leads to its own demise and itself dies out. A successful fungus co-exists with its host tree, so they will both survive.”

http://www.bbc.co.uk/news/science-environment-20680252

Ash dieback has been been found in a sapling on private land in Somerset, Defra has confirmed.

It has since been destroyed to prevent any contamination.

Defra said the infected sapling would have been carried in as part of a batch and planted, rather being infected with airborne spores.

Defra said it would be “very, very bad luck” for the disease to have spread in the short time it was in the county.

http://www.bbc.co.uk/news/uk-england-somerset-20511539

The Defra action plan has an air of sanity conspicuous by its absence from every other domain of government policy. The ban on imported ash trees remains in place; no ash is to be moved around; diseased trees in nurseries and young plantations have to be destroyed but established trees with signs of dieback need not come down: how will we identify resistant strains if every tree is felled at the first sign of infection? (C. fraxinea, Defra added, does not move directly from a diseased tree to a healthy one, but ‘only via the leaf litter’.) For the moment there is relative calm, even if the prognosis for Britain’s population of common ash (fraxinus excelsior)

Plants have always been moved about – it’s a point Rackham makes – but a voyage on a sailing ship was long enough for a pathogen to die, or kill the specimen, before arrival. On a steamship the odds of survival improved. C. fraxinea is one of many globetrotter diseases attacking oak, chestnut, alder, Corsican pine, new generations of elm and several other species, in a world of 24-hour deliveries.

The fungus has been detected near the Channel and it has taken firm hold in the woodlands of the Haute-Saône in north-eastern France. The French, who are normally interventionist (they spray their oak woodlands from helicopters), have struck a fatalistic note on C. fraxinea, which arrived about five years ago. They made the same case against felling that Defra made in November, but they believe the fungus extends its territory at a rapid rate, moving at 150 km a year, against the Woodland Trust’s estimate of 20-30 km.

Wait-and-see has prevailed over a policy of widespread felling, but another line of argument will open up in the spring and summer as existing damage becomes visible and the disease makes seasonal headway. The idea that C. fraxinea can be zapped with a clever chemical is not fashionable: conservationists don’t like it, scientists doubt it can be done and governments are uncertain what products it’s appropriate to license.

http://www.lrb.co.uk/v34/n23/jeremy-harding/diary

The seedlings that were placed into the ground came from generations of backcross breeding that date to the early 1980s. Matt Brinckman, the American Chestnut Foundation’s Mid-Atlantic Regional Science Coordinator, said the project began by crossing an American chestnut with a Chinese chestnut, which is resistant to the blight. The hybrids that were in turn resistant to the blight were crossed again with American chestnut — and again and again until scientists obtained a crossbreed that was 15/16 American chestnut and only 1/16 Chinese chestnut.

The American Chestnut Cooperators’ Foundation was co-founded by Gary Griffin, a plant pathologist at Virginia Tech. Instead of crossbreeding, that group has focused on finding the few remaining large American chestnut trees that have demonstrated partial blight resistance.

“We try to interbreed those to obtain greater levels of blight control,” Griffin said. “There aren’t many of these specimens, but we’ve found them and have been working with them for more than 30 years.”

http://www.roanoke.com/news/roanoke/wb/317311

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