- The total cost of Ash dieback to the UK is estimated to be £15 billion
- Half of this (£7 billion) will be over the next 10 years
- The total cost is 50 times larger than the annual value of trade in live plants to and from Britain, which is the most important route by which invasive plant diseases enter the country
- There are 47 other known tree pests and diseases that could arrive in Britain and which may cost an additional £1 billion or more
The predicted costs arise from clearing up dead and dying trees and in lost benefits provided by trees, e.g. water and air purification and carbon sequestration. The loss of these services is expected to be the biggest cost to society, while millions of ash trees also line Britain's roads and urban areas, and clearing up dangerous trees will cost billions of pounds.
Dr Louise Hill, researcher at Plant Sciences at the University of Oxford and lead author of the study, said: 'The numbers of invasive tree pests and diseases are increasing rapidly, and this is mostly driven by human activities, such as trade in live plants and climate change. Nobody has estimated the total cost of a tree disease before, and we were quite shocked at the magnitude of the cost to society. We estimate the total may be £15 billion - that's a third more than the reported cost of the foot-and-mouth disease outbreak in 2001. The consequences of tree diseases for people really haven't been fully appreciated before now.'
Dr Nick Atkinson, senior conservation advisor for the Woodland Trust and co-author of the paper, said: 'When Ash dieback first entered the country, no one could have fully predicted the devastating impact it would have on our native habitats. To see how this has also affected our economy speaks volumes for how important tree health is, and that it needs to be taken very seriously.
'It is clear that to avoid further economic and ecological impacts, we need to invest more in plant biosecurity measures. This includes better detection, interception and prevention of other pests and diseases entering the country. We need to learn from past mistakes and make sure our countryside avoids yet another blow.'
The scientists say that the total cost could be reduced by replanting lost ash trees with other native trees, but curing or halting the disease is not possible. They advise that the government's focus now has to be on preventing introductions of other non-native diseases to protect our remaining tree species.
- A nationwide replanting scheme could reduce the overall cost by £2.5 billion, by ensuring that lost ecosystem services are replaced
- Greater focus on and investment in biosecurity and sourcing of safe plant material is needed to keep new diseases out
- Introduce far tighter controls on imports of all live plants for planting, as this is the largest pathway through which tree diseases are introduced
Ash dieback is a fungal disease, originally from Asia, which is lethal to Europe's native ash trees. It was first found in Britain in 2012 and is thought to have been brought to the UK years earlier on infected imported ash trees. It is expected to kill 95-99% of ash trees in Britain.
Read the full paper once the embargo lifts here: https://www.cell.com/current-biology/fulltext/S0960-9822(19)30331-8
The DOI will be 10.1016/j.cub.2019.03.033.
For more information and interview requests please contact the University of Oxford press office at [email protected] or 01865 280730.
Or the Woodland Trust press office at [email protected] or 01476 581121.
Notes to editors
The University of Oxford has been placed number 1 in the Times Higher Education World University Rankings for the third year running, and at the heart of this success is its ground-breaking research and innovation. The university is world-famous for research excellence and home to some of the most talented people from across the globe. Their work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of its research sparks imaginative and inventive insights and solutions.
Sylva Foundation is an environmental charity working to bring trees and people closer together. It formed the Oxford-Sylva Graduate Scholarship, which co-funded lead author Dr Louise Hill, to foster a robust tree and forest resource in the face of environmental change. It has played a lead role in developing a climate change action plan for Britain's forests.
The Woodland Trust is the largest woodland conservation charity in the UK. It has over 500,000 supporters. It wants to see a UK rich in native woods and trees for people and wildlife. The Trust has three key aims: i) protect ancient woodland which is rare, unique and irreplaceable, ii) restoration of damaged ancient woodland, bringing precious pieces of our natural history back to life, iii) plant native trees and woods with the aim of creating resilient landscapes for people and wildlife. Established in 1972, the Woodland Trust now has over 1,000 sites in its care covering over 22,500 hectares. Access to its woods is free.
Fera Science Limited, formerly the Food and Environment Research Agency, is a joint private/public sector venture between Capita plc and Defra. Using original thinking applied to support sustainable global food security our vision is to support our partners to respond to the challenges ahead through original thinking and world-class science. Fera turns expertise and innovation into ways to support and develop a sustainable food chain, a healthy natural environment, and to protect the global community from biological and chemical risks.
This work was partially funded by the Department for the Environment, Food, and Rural Affairs.