[walwyn]

A disease which has destroyed many thousands of Californian oaks has been found for the first time in several well-loved British tree species.

It is a fungus called sudden oak death, and till now it had been found only in UK shrubs and a tree native to the US.

But the Forestry Commission says the disease has now struck beech, horse chestnuts and holm oaks in Cornwall.

There is no known cure for the disease, which kills the trees' bark and is thought liable to affect other species.

The fungus, known as Phytophthora ramorum, has killed 80% of one oak species in the western US.

It was discovered last year in viburnum plants in British garden centres, and there have been more than 300 subsequent outbreaks in plant nurseries, and in some wild rhododendrons.

http://news.bbc.co.uk/1/hi/sci/tech/3291011.stm

[Michael Frankis]

Hi Walwyn,

Heard about this yesterday. Rather depressing news. Hard to predict yet what damage it might cause.

Michael

[walwyn]

80% loss seems devastating. Could it be as bad a Dutch Elm?

Defra fact sheet:
http://www.defra.gov.uk/planth/pestnote/sudden.htm

[Joern Lehmhus]

In germany over the last years I got the impression that the situation with the elms is very slowly getting better, with some old trees that survived and some young growth, in some areas even a lot.

But I don´t know if it is really better or just an illusion.

but being involved with plant diseases in my job, i am going to predict that P. ramorum will cause massive problems...there have been a lot of warnings by the authorities

[Surreybirder]

This sounds like really bad news. From what I heard on the Beeb, there have been outbreaks in Cornwall and Sussex. The killer fungus is associated with understory of rhododendron. the Forestry commission are conducting a 10km square-based survey of all woodland this winter to try and see how serious the threat is.
The Beeb story focuses on the fact that the loss of conkers would be disappointing for children. But the potential problems to many species of birds is far more serious.
Let's hope it can be contained.

[cjay]

As an amateur Myco myself it is very much a cause for concern. As many of you know the english Oak is very important in the biodiversity structure. Thanks for bringing it to our notice
CJ

[StevieEvans]

Saw this on the TV News this week, yet Defra information is dated Aug/03.
80% of Oaks, hard to imagine.
Terrifying...!
S

[walwyn]

Three sites in Cornwall have been identified as sources of the fungus and are to be cordoned off, some of Lost Gardens of Heligan rhododendrons are being also being burnt.
http://news.bbc.co.uk/1/hi/england/cornwall/3526689.stm

However, apparently the English Oak appears to be immune but not so trees like beeches, conifers, spruces and firs

[Surreybirder]

Originally Posted by walwyn

However, apparently the English Oak appears to be immune but not so trees like beeches, conifers, spruces and firs

I hope you are right!
There was a two-page article on the disease and a leader in the Times last week. Basically praising the authorities for their thoroughness in surveying every 10km square for the disease, and giving its history. Probably imported from the Netherlands on nursery plants, apparently. They say it's impossible to monitor all plant imports. Rhododendrons seem to be prime suspects as carriers although the disease doesn't kill them.