16 June 2011

Forestry Disease Battle 'Goes Sky-high'

Airborne plans by the Department of Agriculture and Rural Development (DARD) to combat the spread of an especially virulent tree disease have been discussed this week.

The NI DARD Minister Michelle O'Neill was briefed on P. ramorum and told that it has a potential to attack a wide range of woody plants and could cause significant damage to woodland and other habitat.

The Minister met with her officials, who will be taking part in a two-day helicopter survey of local forests, to check for likely symptoms of the disease caused by the fungus like organism, Phytophthora ramorum.

She was told that eight infected sites have now been confirmed in woodlands on the Antrim Plateau and one in mid Down since the disease was first diagnosed in August 2010.

Since then, felling has been completed in approximately 300 hectares of public forest estate and a further six hectares of private woodland to combat the spread of this disease.

The disease has also been discovered in larch woodland in the south of Ireland, England, Scotland and Wales.

Speaking ahead of the helicopter survey, the Minister said: "The aim of this survey is to quickly identify any new suspicious symptoms on larch, which can then be followed up by a more detailed ground inspection of the suspect sites.

"The helicopter team, including two DARD staff, will use an on board digital SLR camera to record larch crown condition, in both public and private woodland," she said afterwards.

She added: "The helicopter survey will help us to focus subsequent ground inspection of suspect sites, and DARD staff will examine and record symptoms in more detail, which together with field and lab tests and proximity of earlier outbreaks, will help us determine whether a new site is infected or not."

Stressing the need for ongoing vigilance against the disease, the Minister concluded: "Following bud burst in spring and the growth of new larch needles and shoots in early summer, all woodland owners and managers must renew their vigilance for symptoms of the disease.

"Unfortunately, identifying symptoms of the disease will be made more difficult this year because of widespread browning of many trees, including larch, which we believe is associated with the exceptionally strong winds of late May. "

However, she said that: "In most cases, we would expect these trees to recover during the year, unless they suffer further extreme events," advising, "if symptoms unrelated to wind exposure, such as small groups of trees browning in otherwise healthy woodland, or resin bleeding from the tree crown, or failure of larch trees to recover from browning, are observed, these should be reported to the Department."

This may be a significant threat, as there are approximately 3,500 hectares of Japanese, European and hybrid larch or woodland with a component of these species in DARD woodland in NI, which represents about 6% of all of DARD woodland areas.

(BMcC/GK)