Tens Of Thousands of Oak Trees dying from disease
Pastor Dale Morgan
Tens Of Thousands of Oak Trees dying from disease*
By Jasper Copping
Last Updated: 12:01am GMT 13/01/2008
For centuries it has been a steadfast symbol of England, but the mighty
oak now faces a battle for survival as a devastating disease advances
through the nation's forests.
Oak tree: Thousands of oaks dying from disease
English heritage: the oak, a symbol of national pride and endurance, is
succumbing to a spreading new pestilence
The virulent contagion, called oak decline, slowly kills the plant from
the top down. It has spread to at least 100 areas around the country,
with thousands of trees affected.
Experts fear that warmer temperatures caused by global warming will see
the disease extend its reach even more quickly in future years.
They also believe that oak decline could prove as damaging to the
English countryside as Dutch elm disease did in the 1970s.
The Forestry Commission has launched an investigation, fearing that the
number of reported cases could be the tip of the iceberg. It is urging
landowners to notify officials of any sign of the disease.
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John Tucker, from the Woodland Trust, said: "There are some real
problems for our oaks. Oak decline is something we should be paying
particular attention to."
In one hotspot, in Charnwood Forest, in Leicestershire, which was first
affected four years ago, 20 trees have died and hundreds more are now
infected.
Mark Graham, the wildlife officer for Charnwood borough council, said:
"We've found 250, but there could be many more. Oaks are the most
important tree in the woodland, because of the number of other plants
and insects they can support.
"Lowland Britain has a lot of oak trees and if other sites have the same
experience as us it will be devastating. We would be looking at the same
sort of thing as Dutch elm disease."
The first sign that a tree has oak decline is a yellowing of foliage.
Leaves start to thin and the plant dies from the top downwards, often
taking on a "stag-headed" appearance, where large, leafless branches
push upwards like a stag's antlers. Cankers in the trunk can bleed a
black, pus-like fluid.
It weakens the oak's ability to fight deadly attacks from insects or
fungi and means that the trees, which can live for 400 years, are dying
as early as 40.
Oak decline has been present in the UK since at least the 1920s, when
there was an outbreak linked to defoliation of trees by the oak roller
moth, which was abundant at the time. There was also an outbreak in the
late 1980s and early 1990s, where it was found at about 40 sites.
Now the disease has returned in an "acute" form, killing trees very
quickly and allowing less time for woodlands to recover, a condition
which has alarmed wildlife experts.
It has also struck at a time when the oak, a national symbol, faces
other emerging threats. These include the oak processionary moth, which
has travelled north from the Continent in recent years and has already
been linked to the deaths of trees in Kew Gardens, London, and a fungus
linked to a condition called sudden oak death, which has killed tens of
thousands of trees in America.
Although English oaks have so far proved resistant to sudden oak death,
experts fear they could become increasingly vulnerable as they are
weakened by oak decline.
Joan Webber, a tree pathologist at the Forestry Commission, said: "We're
getting more cases of oak decline being reported, and we're seeing a
much more acute form of decline now where trees die very quickly.
"We're seeing cases where trees go from showing the early symptoms to
death in a matter of about three years and that is pretty rapid. It can
now move very, very quickly."