This article is from the source 'guardian' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at http://www.guardian.co.uk/environment/shortcuts/2013/may/21/sweet-chestnut-blight-threat-trees

The article has changed 2 times. There is an RSS feed of changes available.

Version 0 Version 1
Sweet chestnut blight – the latest threat to Britain's trees Sweet chestnut blight – the latest threat to Britain's trees
(4 months later)
Hot on the heels of ash dieback, it seems that sweet chestnuts are now under threat. This week, the UK government announced that it was to ban imports of sweet chestnut saplings from foreign nurseries in an effort to stop the spread of a fungal blight that is already killing chestnuts across Europe and North America and now threatens the UK's estimated 44m specimens. An infection of the blight - known as Cryphonectria parasitica - is usually fatal to sweet chestnuts. It causes a characteristic bright brown cankered bark, in contrast to the greenish colour of normal bark. After it was first detected in North America in the 1930s it went on to kill an estimated 3.5 billion trees within 20 years.Hot on the heels of ash dieback, it seems that sweet chestnuts are now under threat. This week, the UK government announced that it was to ban imports of sweet chestnut saplings from foreign nurseries in an effort to stop the spread of a fungal blight that is already killing chestnuts across Europe and North America and now threatens the UK's estimated 44m specimens. An infection of the blight - known as Cryphonectria parasitica - is usually fatal to sweet chestnuts. It causes a characteristic bright brown cankered bark, in contrast to the greenish colour of normal bark. After it was first detected in North America in the 1930s it went on to kill an estimated 3.5 billion trees within 20 years.
The news comes just months after the government banned the import of ash saplings in the – some say – now forlorn hope of preventing the spread of a fungal disease known as "ash dieback". With other tree diseases also in the news – the oak processionary moth has been detected in the Greater London area and Berkshire – there is a swelling sense that many tree species are facing an existential threat.The news comes just months after the government banned the import of ash saplings in the – some say – now forlorn hope of preventing the spread of a fungal disease known as "ash dieback". With other tree diseases also in the news – the oak processionary moth has been detected in the Greater London area and Berkshire – there is a swelling sense that many tree species are facing an existential threat.
Owen Paterson, the environment secretary, this week announced that a national plant health risk register is to be established, following the recommendation of a biosecurity taskforce he had convened in light of the onset of ash dieback. But which trees are next in line for some life-threatening blight? The taskforce's report contains a list of exotically named "potential threats" yet to be detected in the UK, including the "eight-toothed Europe spruce bark beetle", citrus longhorned beetle, red oak borer, oak wilt, pine processionary moth, plane wilt (which has affected 80% of plane trees in some parts of France), pine pitch canker and brown spot needle blight. And what elms still remain in the UK could be finished off by the zigzag elm sawfly, which has "spread quickly" from Asia into continental Europe.Owen Paterson, the environment secretary, this week announced that a national plant health risk register is to be established, following the recommendation of a biosecurity taskforce he had convened in light of the onset of ash dieback. But which trees are next in line for some life-threatening blight? The taskforce's report contains a list of exotically named "potential threats" yet to be detected in the UK, including the "eight-toothed Europe spruce bark beetle", citrus longhorned beetle, red oak borer, oak wilt, pine processionary moth, plane wilt (which has affected 80% of plane trees in some parts of France), pine pitch canker and brown spot needle blight. And what elms still remain in the UK could be finished off by the zigzag elm sawfly, which has "spread quickly" from Asia into continental Europe.
"There are a variety of pests and diseases already in the UK and many more on the continent heading our way, but the biggest threat to UK trees could be one we don't currently know about," says Austin Brady, head of conservation at the Woodland Trust. "It's hard to predict how pests and diseases present elsewhere might behave on reaching the UK. Sudden oak death is a good example of this as it affects oak trees in the US, but it is now spreading via rhododendrons and having a devastating affect on Japanese larch trees in the UK.""There are a variety of pests and diseases already in the UK and many more on the continent heading our way, but the biggest threat to UK trees could be one we don't currently know about," says Austin Brady, head of conservation at the Woodland Trust. "It's hard to predict how pests and diseases present elsewhere might behave on reaching the UK. Sudden oak death is a good example of this as it affects oak trees in the US, but it is now spreading via rhododendrons and having a devastating affect on Japanese larch trees in the UK."
Variety is the best defence, says Brady. Identifying and planting a single, seemingly resistant species might prove futile in the long run: "It is important to be vigilant, look after our trees and, when planting, ensure a mix of species is used so that we build resilient landscapes that can withstand future threats."Variety is the best defence, says Brady. Identifying and planting a single, seemingly resistant species might prove futile in the long run: "It is important to be vigilant, look after our trees and, when planting, ensure a mix of species is used so that we build resilient landscapes that can withstand future threats."
Our editors' picks for the day's top news and commentary delivered to your inbox each morning.