December 2012


Nurseries infected with the deadly fungus set to wipe out Britain’s 80m ash trees have been removed from the official map of the outbreak the Guardian can reveal, after nursery owners complained that being identified might hurt their business.

Officials said permitting anonymity encourages nursery owners to come forward and report infections, but critics say concealing the identity of infected nurseries means the public and scientists trying to fight the epidemic do not have the full facts.

http://www.guardian.co.uk/environment/2012/dec/23/ash-dieback-infected-nurseries-map

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Thousands of deer are to be shot to save ash trees from a killer disease.

About 400,000 animals are normally culled every year to keep numbers down.

But conservationists believe thousands more must go to allow young ash saplings to grow and replace the trees suffering from ash dieback disease, Chalara fraxinea.

‘We will use a combination of fencing and deer management. But if you simply use fencing, deer just push through or decimate neighbouring woodland.’

The RSPCA said a cull would be acceptable if overgrazing threatened the landscape.

http://www.dailymail.co.uk/news/article-2252403/Thousands-deer-shot-help-stop-spread-ash-tree-disease.html#ixzz2GR0UvvE8

Two trade bodies, the Horticultural Trades Association and the Confederation of Forest Industries, warned the Commission of the potential threat of fungal disease in 2009.

But despite this 70,400 trees were brought in from abroad and now ash dieback- or chalara fraxinea – is now threatening to wipe out 80 million trees in Britain.

The infected Forestry Commission sites include Thetford Forest, in Norfolk, one of the biggest lowland forests in England with more than 19,000 hectares of woodland.

Also affected are Rendlesham Wood, a 1,500 hectare forest in Suffolk; Theberton Wood, a 25 hectare patch of woodland in Suffolk; Eggringe Wood, which forms part of a stretch of woodland on the Kent Downs covering 1,598 hectares; and the 400 hectare Elham Park Wood in east Kent.

The Forestry Commission also had to destroy 50,000 saplings at Dalbeatie Forest in Dumfries and Galloway after they were found to be infected.

It is understood the 70,000 imported ash trees represented 4.2 per cent of the total planted.

http://www.telegraph.co.uk/earth/earthnews/9769588/Forestry-Commission-planted-70000-imported-ash-trees-despite-warnings.html

According to Kraj, W., Zarek, M. & Kowalski, T. (2012) there are several strains of C. fraxinea in Poland.

As has been widely reported, ash dieback is now established in Lithuania, Latvia, Estonia, Baltic Russia (Kaliningrad), Finland, Sweden, Denmark and Germany, as well as Poland and these are all countries with a Baltic shore. The fungus is also now widespread in southern Norway, just outside the Baltic.

In the south the disease has advanced steadily across central Europe as far as France, Italy, Romania and other countries.

The terrestrial route seems consistent with propagation mainly by airborne spores of the H. pseudoalbidus stage and maps produced in France illustrate this well.  In following the advance of C. fraxinea, it is important to try and discover the first reports in different areas as (a) the fungus spreads very rapidly and (b) once discovered far more people start looking for it. Also it has to be borne in mind that it may have been present for some years before being detected. Because of this and other factors, possible dispersal routes become unclear quickly.

The terrestrial route seems consistent with propagation mainly by airborne spores of the H. pseudoalbidus stage and maps produced in France illustrate this well.  In following the advance of C. fraxinea, it is important to try and discover the first reports in different areas as (a) the fungus spreads very rapidly and (b) once discovered far more people start looking for it. Also it has to be borne in mind that it may have been present for some years before being detected. Because of this and other factors, possible dispersal routes become unclear quickly.

increasingly suggestions are being made that the pathogen has been present in Britain and elsewhere since well before its first report and, if this is correct, at least some nursery stock may have been infected from local woodlands after importation.

So far as the British Isles is concerned, virtually all the current records of Chalara from the wider environment (i.e. not from nurseries or recent plantings) are on the eastern side of the country, many close to the coast. While wind borne spores from mainland Europe may be responsible for many of these outbreaks, most are also near ports, places where there are many arrivals and departures of people and goods to and from other countries. This is particularly apparent in the area around Dover and Folkestone (Forestry Commission, 2012).

Acute oak decline, which is thought to have first emerged less than 30 years ago, affects trees that are more than 50 years old. Half of oaks in some English woods are already infected.

Peter Goodwin, the co-founder of Surrey-based charity Woodland Heritage, warned that the disease was “far more serious” than ash dieback, which has captured headlines over fears that it will spread to most of the UK’s 92 million ash trees.

“The Department for Environment, Food and Rural Affairs are absolutely culpable in under-funding this problem, so my charity Woodland Heritage began raising money and has done some incredible things to bolster that team of scientists, and we are getting results now,” he told the East Anglian Daily Times.

Acute oak decline is likely to have a complex cause involving both a particular kind of beetle and various species of bacteria that have been found together in affected trees.

http://www.telegraph.co.uk/earth/countryside/9762106/Government-failed-to-fund-research-into-deadly-oak-disease.html

A Queen Mary scientist will embark on a new project to decode the ash tree’s entire genetic sequence in the hope of stopping Britain’s trees from being completely devastated by the Chalara ash dieback fungal disease.

Project leader, Dr Richard Buggs from Queen Mary’s School of Biological and Chemical Sciences, said: ‘Sequencing the ash genome is a foundational step towards discovering the genetic basis of resistance to ash dieback: the future of ash trees in Britain may depend on this. At Queen Mary, University of London we will build on our experience of sequencing the birch genome to optimise this ash genome project.’

A small percentage of ash trees in Denmark are showing some resistance to the fungus. By decoding the tree’s genetic sequence, scientists will take a crucial first step towards identifying the genes that confer this resistance.

The researchers expect to have a first draft of the tree’s entire genetic sequence by August 2013. Once sequencing is complete, they plan to make it publicly available for use by other researchers.

http://www.qmul.ac.uk/media/news/items/se/88532.html

Mr Gardiner said if importing low-quality woodchip from Poland, Belgium or Denmark where there is infection up to 80%, then “it is unlikely that you are going to get non-contaminated, low-grade woodchip”.

The risk was much higher than moving the fuel around the UK, where the infection rate was much lower by comparison.

Dr Steve Woodward, plant pathologist at Aberdeen University said, “There is the potential for young shoots that have been put into the admixture of chips and chipped up themselves to carry the infection so if the material was coming in the correct time of year which would be June to September and if that material was contaminated and should it be left lying around anywhere where it was of suitable humidity where it could produce the fruiting bodies then that’s when it presents the risk.”

http://www.telegraph.co.uk/earth/countryside/9757345/Woodchip-imports-should-be-banned-to-stop-ash-dieback.html

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