Conservation Concerns

Disease

Historic parks and landscapes, often have important collections of susceptible plants and are therefore under threat and could also be a source of infection for sites beyond the historic boundaries. Care is needed in the movement of susceptible species into and out of sites. For centuries the British Isles has had its own natural barrier to invasion by many damaging organisms - the sea. However increasing global trade in plants, timber and the use of wood-based packaging provides many pathways for pests and pathogens to escape their native habitats and enter new areas.

Over the past decade, several new pests and diseases such as Ramonum Dieback have been found in the UK, with some serious consequences for historic sites. Despite the endeavours of many national organisations, some pests and diseases do become established, so advice and research is required in order to develop effective containment and management procedures.

DEFRA and Forestry Commission websites give more information and advice on Tree Pests and Diseases.

Phytophthora, Bleeding Canker of Horse Chestnut

Bleeding Canker of Horse Chestnut (Aesculus hippocastanum) was first recorded in the UK in the 1970s. Observations of infection, have become increasingly common in recent years. It is caused by Phytophthora cactorum and P. citricola. Although the process of infection is unknown, Phytophthora spores tend to be dispersed in wet conditions.

Ramonum Dieback or Sudden Oak Death

Phytophthora ramorum is a fungus causing the death and decline of large numbers of native oaks and other woodland species in California and Oregon. A disease associated with this organism has been given the name ‘Sudden Oak Death’ in the USA. As the host range includes a wider number of species than oaks, the name of Ramorum Dieback has been suggested for this disease in the U.K.