Lessons from Dutch Elm Disease in Assessing the Threat from Sudden Oak Death

Project Status: Completed
Type of Project: Research Project
Principal Investigator: Dr Clive Potter, Imperial College, London (Email) (Website)

Publications, Data and Other Outputs
Review of Programme to Contain and Eradicate Phytophthora ramorum and Phytophthora kernoviae
Policy and Practice Note

 

Objectives

This project will explore the extent to which previous experience of a major tree disease pandemic, Dutch elm disease, the cause of a widespread death of trees and landscape change in the UK during the 1970s, can offer a point of comparison for dealing with the more recent threat of sudden oak death. While the two diseases are very different in nature and impact, the legacy of Dutch elm disease in terms of policy learning, public memory and personal experience deserves to be re-examined at this point in the policy cycle, as lessons we have learnt from disease epidemics affecting forests and trees in the past can be helpful in understanding the challenges of the future.

Disease epidemics affecting forests and trees are now seen as major threats to biodiversity, landscapes and ecosystem function throughout the world. Compared to diseases affecting livestock or agricultural crops, where acute but usually short-lived ecological and economic impacts can be addressed by established control measures, the impact of forest diseases is often cumulative, long term and difficult to control. Sudden oak death is an emerging forest disease that has already reached epidemic levels in the coastal forests of central California and its recent appearance in host species in the UK has raised concern that a wide range of tree types in this country may now be at risk.

The project draws on archival research and interviews with people directly involved in the original Dutch elm disease outbreak to reconstruct the progress of the disease across the UK and subsequent (failed) attempts to deal with it. It then uses modelling and reconstructive photographic techniques to compare this trajectory with the possible spread of sudden oak death under a number of alternative management scenarios, and to recall the impact on landscapes throughout lowland England. Focussing on a small number of case studies, the research further visualises the landscape implications of varying degrees of infection, impact and spread for sudden oak death. These visualisations are used to explore public memory of Dutch elm disease and perception of risk and as a mechanism for eliciting the public's willingness to pay to compensate for or avoid such changes. We compare the costs of disease management with these valuations to assess the management options in cost-benefit terms. The project concludes by presenting these findings to a stakeholder jury charged with reaching a series of 'verdicts' on the lessons of Dutch elm disease and the likelihood and manageability of a future outbreak of sudden oak death.