It estimates the total cost of chalara to the UK at £15bn, half of which will be over the next 10 years. The researchers say the total cost is 50 times greater 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.
The predicted costs arise from clearing up dead and dying trees and in lost benefits provided by trees –for example, water and air purification and carbon sequestration.
“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,” said Dr Louise Hill, researcher at Plant Sciences at the University of Oxford and lead author of the study.
“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.”
The study advocates a nationwide replanting scheme; greater focus on and investment in biosecurity and sourcing of safe plant material; and introducing far tighter controls on imports of all live plants for planting.
