Ash Dieback disease threatens Devon's hedged landscape – let's ...

Ash Dieback disease threatens Devon’s hedged
landscape – let’s record what we have before it’s too
late.
Ash dieback looks set to have a major impact on Devon’s countryside, much of
which is defined by its rich networks of hedges. Ash is one of our three main
hedgerow trees, along with oak and beech, and makes up about one sixth (16%) of
their shrubby growth. If the ash goes, and evidence from the continent suggests we
will lose 90% of them, then our landscape will change dramatically.
The Devon Hedge Group encourages people throughout the county not only to look
out for signs of the disease, and report any cases, but also to record fine mature
hedgerow ash trees. Parish inventories of hedgerow ash would be particularly
valuable.
We know that Dutch elm disease, which hit us in the 1970s, had a devastating effect,
but have virtually no records of what the countryside used to look at before the
disease struck.
Brian Beasley, Dartmoor National Park Authority’s Tree and Landscape Officer, says
“If we record hedgerow ash trees now, then at least after Ash Dieback hits we will
know what the countryside used to look like, and can perhaps attempt to restore it in
the future. The Devon Hedge Group would very much like to hear from individuals
and communities interested in making such records, whether of particularly fine or
valued specimens, or through fuller surveys”.
The Devon Hedge Group urges people not to take pre-emptive action to fell ash
trees which are not infected. Fortunately, old trees show much more resistance to
the disease than young ones, and may survive for years before they succumb or
even not die at all.
It is old, mature trees that are both most important for wildlife and for the landscape.
Ash is one of our finest fire woods, another reason why its loss will be so hard to
take – many farmers currently take an occasional firewood crop from their hedges,
and ash and is most valued of all trees for this purpose.

Contacts:
Brian Beasley. Dartmoor National Park Authority, Trees and Landscape Officer.
01626 831002. bbeasley@dartmoor.gov.uk.
Robert Wolton. Chairman, Devon Hedge Group. 01837 810416.
robertwolton@yahoo.co.uk.
Photos of ash trees in hedges are available free from Robert Wolton
Further information
The disease
Ash dieback disease is a fungal infection caused by Chalara fraxinea. The disease
causes leaf loss and crown die back in affected trees. Infected trees are unlikely to
survive and it is predicted that over 90% of Britain’s ash trees could be lost to the
infection. Young trees are likely to die in the first season of infection with large
mature trees taking several years to die.
To date the infection has been confirmed at 549 sites throughout the UK, 24 in
nurseries, 336 on newly planted sites and 189 in the wider environment. Most of the
infected sites are in the south east and some of these infections may have been
caused by wind carried spores from the continent. Few infected sites have been
identified in the south west, most of these infected sites are on recently planted sites
although one site trees in the wider environment have been infected.
What does ash die back disease look like?
There are a wide range of symptoms associated with ash dieback including:
foliage wilt – black/brown leaves may be retained;
shoot dieback with brownish to orange discolouration, often multiple
shoots
elongated angular stem lesions, often diamond shaped.
small white fruiting bodies growing on stalks of fallen ash leaves
staining of wood under bark
For further information on identifying the disease visit the Forestry Commission’s
web site at http://www.forestry.gov.uk/chalara
What to do if you spot unhealthy ash trees
Any suspected sighting should be reported to the Forestry Commission via the
Chalara helpline (plant.health@forestry.gsi.gov.uk). The Forestry Commission or
FERA will investigate and if a case is confirmed they will take appropriate action.
Unlike Phytophtora DEFRA is not recommending total removal of infected trees, they
are requiring the removal of infected trees in nurseries and on newly planted sites,
but woodland and hedgerow trees will be left in situ. It is hoped that some trees will
show resistance to the disease and they can used as a seed source for the next
generation.

The wildlife of ash trees
Ash supports much wildlife, with quite a few species depending solely on it for their
survival. Trunks frequently support rich moss and lichen communities, and moths
like the Coronet are dependent on it – their caterpillars will eat only ash leaves. The
seeds, or ‘keys’, provide much food for birds, including rarities like the Hawfinch, and
when they fall to the ground for small mammals. Rot holes in ash are particularly
good for rare flies and beetles, while other signs of maturity, like cracks, splits and
hollows, provide roosting and breeding places for many types of bat.
Devon’s hedges
Devon’s hedges are truly world class. In a country famed for its hedgerows, Devon
has a larger and more intact hedgerow heritage than any other county in
Britain. Most of the county’s hedgerows are ancient, most dating back to Medieval
times or before, and through their rich and intricate patterns tell the story of Devon’s
landscape and farming traditions over many centuries. They are a distinctive feature
of our countryside, important culturally, of great value to wildlife including threatened
species like the dormouse, and deliver numerous other public benefits like soil
protection, water regulation and carbon storage.
The Devon Hedge Group
The Devon Hedge Group is a forum of organisations and individuals interested in
working together to promote the appreciation and conservation of hedges found
across the county. Members of the Group represent the full range of interests
associated with hedges in Devon, including agriculture, the conservation of wildlife
and landscape, and historical and cultural values.
12 August 2013, Devon Hedge Group