Information on Loughborough

Scientists Identify Bacteria in Loughborough Trees affected by Acute Oak Decline

Posted on 09/08/2008

oak tree in Charnwood

SCIENTISTS have moved a step closer to identifying the cause of a condition which is affecting Oak trees in a number of woods.

The condition, which has been found in Charnwood Borough Council-owned Booth Wood, Gorse Covert and the award winning Outwoods as well as a number of other local sites including Swithland Wood, has been described as an episode of ‘acute oak decline’.

Pathologists from the Forestry Commission’s Forest Research Agency have discovered a number of bacteria in samples taken from trees

Further tests are now being carried out on saplings in a bid to pinpoint which bacteria are responsible but it could be several months before the exact cause is known.

Dr Sandra Denman, a Senior Forest Pathologist with Forest Research, said: “Our initial tests are consistently indicating that bacteria from three different genera, or groups, are associated with the bleeding areas visible on the oak trees in Loughborough.

“However, we need to do a lot more work to identify the particular species of the bacteria and to find out the role that each one plays in this episode of acute oak decline.

“Research of this kind if very difficult to do and takes many months, even years, but we are encouraged by the progress we have made so far.”

The condition was first spotted in Booth Wood in 2002 when it affected a couple of trees a year but by 2007, more than 200 trees had been infected.

Oaks at a number of other local sites including the Outwoods were then discovered to have symptoms of the condition - bleeding cankers and a rapid deterioration in health.

In autumn 2007 and March this year, the Forestry Commission’s experts took a number of samples of roots from some of the diseased oak trees.

Soil around them was also taken for analysis in a bid to establish whether the deteriorating health of the trees can be linked to any soil-borne or root-rotting organisms.

Mark Graham, Charnwood Borough Council’s Wildlife Officer, welcomed the findings but said it would be some time before the exact cause would be known.

He said: “It’s encouraging that some progress has been made, although we are still a long way from having a definite answer.

“This type of research is slow by its very nature but it’s good there have been some developments in pinpointing what is responsible for this condition.”

Cllr Peter Lewis (Conservative Councillor for Loughborough Nanpantan), Charnwood Borough Council’s Cabinet member for Leisure, said: “We care passionately about our woodland in Charnwood and are delighted the Forestry Commission’s Forest Research Agency has made progress in identifying what’s causing this condition.

Further information about oak decline is available from the Forest Research web site, www.forestresearch.gov.uk

Background Information

The terms "decline" and "dieback" are used by foresters and arborists to describe a condition in which a number of damaging agents interact with one another to weaken trees and bring about their deterioration, sometimes resulting in premature death. Decline and dieback can either be ‘chronic’ (slow and progressive) or acute (see below). Damaging agents associated with decline and dieback can include insects, diseases and extreme weather. Healthy trees can usually withstand sporadic attacks by pests or diseases when they occur singly, but often suffer significant damage if they occur simultaneously or when trees are stressed by other factors, such as drought or flooding. In cases of acute decline the trees experience a rapid deterioration in health, sometimes leading to their deaths within as little as four years from the onset of first symptoms.

This contrasts with chronic decline, which is a slow deterioration over many years and from which the trees can often recover, particularly if there is a reduction in the factors that cause the decline.

The Forestry Commission is the government department for forestry in Great Britain. Forest Research is an agency of the Commission that undertakes world-class scientific research and technical development relevant to forestry. For further information, visit www.forestry.gov.uk and www.forestresearch.gov.uk.