asked Her Majesty's Government:

Further to the Written Answer by the Parliamentary Under-Secretary of State for Environment, Food and Rural Affairs, Mr Ben Bradshaw, on 15 September 2004 (Official Report, Commons, col. 1578W), whether the Forestry Commission has undertaken any further investigation into the incidence of Sudden Oak Death syndrome; and if so, with what result.[HL3829]

The research agency of the Forestry Commission (Forest Research) has continued investigation into the disease caused by the pathogen Phytophthora ramorum (known as Sudden Oak Death in the USA). These investigations also include another Phytophthora pathogen, recently named P. kernoviae. Only discovered four to five years ago in Britain, both pathogens are considered recent introductions. Both attack the foliage of certain ornamental and understorey shrub species such as Rhododendron, where they produce spores. When heavy infestations of these “foliar” hosts occur, nearby trees become infected, resulting in extensive bark killing and even mortality. Beech is very susceptible and is most at risk from both pathogens, but P. ramorum is capable of causing potentially lethal cankers on various trees including southern beech (Nothofagus), turkey oak (Quercus cerris), red oak Q. rubra and sweet chestnut (Castanea sativa). Native oaks show low levels of susceptibility only in laboratory tests and only one individual of sessile oak (Quercus petrea) in woodland has succumbed to a natural P. ramorum infection. Currently, more than 150 P. ramorum outbreaks have been detected on shrubs in gardens and woodlands, mostly in England, but infected trees have only been found at about 10 of those sites. There are about 50 P. kernoviae outbreaks (mainly in Cornwall with a small focus in Wales) but about 20 per cent have affected trees. Efforts at eradicating or containing the disease in woodland concentrates on destroying infected foliar hosts—mainly R. ponticum. However, Forest Research work shows that even when foliar hosts are removed, both pathogens can persist for at least one to three years in soil and litter layers. FR scientists have also shown that both pathogens can be found in debris on footwear, and probably on vehicle tyres, thus providing a mechanism for local spread into new areas.