Hope for ash dieback as Somerset trees show resistance

25.10.2013 15:55

Trees in a Somerset estate have
survived ash dieback for far longer
than previously thought possible –
suggesting there may be potential to
slow the spread of the disease in the
British countryside.
The National Trust said only 10% of
the 6,000 ash trees at its Holnicote
estate, near Minehead, are showing
any signs of the disease, despite
having been infected for five years
longer than any other tree in the UK
so far.
Ash dieback, known as chalara
fraxinea, is present in one other
small plantation nearby but does not
appear to have spread any further,
which the trust said was at odds with
government predictions suggesting it
should have spread further and
infected more trees in this time.
The findings suggest tackling the
disease in the UK is not a lost cause
and control measures could slow the
spread from south-east England,
where the disease appears to have
been wind-blown from mainland
With an estimated 80 million ash
trees in the UK – making up one-third
of the country's tree cover – this
could be good news for the British
landscape, which would be radically
changed if the disease spread in the
coming decades.
Dr Simon Pryor, natural
environment director at the National
Trust, said: "It's important that the
disease has not appeared to have
spread very far.
"Even the trees affected have not
suffered as much as we'd have
expected, and very few have died,
despite apparently having had the
disease for nearly a decade.
"Whilst we don't want to be too
optimistic on the basis of this one
outbreak, this does confirm the view
we've held from the outset that it is
worthwhile removing infected trees
in order to try to slow the spread –
especially in places like this so far
from the south-east.
"We will be asking the government to
look again at its control strategy in
the light of this new evidence – which
to us does not appear to fit well with
current modelling."
The National Trust discovered the
outbreak of ash dieback at Holnicote
in September when undertaking
routine inspections for the disease.
The trees were planted back in 2001
to mark the millennium and pre-date
other outbreaks of the disease by five
It is likely that these trees – like
thousands of others imported to the
UK at the time –1 § were infected
whilst being grown in central Europe