A new report out of Cambridge University has determined that the sudden oak death epidemic in California is unstoppable.
“Sudden oak death – caused by Phytophthora ramorum, a fungus-like pathogen related to potato blight – has killed millions of trees over hundreds of square kilometres of forest in California. First detected near San Francisco in 1995, it spread north through coastal California, devastating the region’s iconic oak and tanoak forests.”
“Our study is the first major retrospective analysis of how the sudden oak death epidemic in California could have been managed, and also the first to show how to deal with a forest epidemic of this magnitude,” explains Cunniffe.
“Even if huge amounts of money were to be invested to stop the epidemic starting today, the results of our model show this cannot lead to successful control for any plausible management budget. We therefore wanted to know whether it could have been contained if a carefully-optimised strategy had been introduced sooner. Our model showed that, with a very high level of investment starting in 2002, the disease could not have been eradicated, but its spread could have been slowed and the area affected greatly reduced.”
The model also indicates how policymakers might better plan and deploy control when future epidemics emerge.
“It is a tool by which we can make a better job next time, because it is inevitable that there will be a next time,” says Professor Chris Gilligan, senior author and also from the Department of Plant Sciences. “With this sort of epidemic there will always be more sites to treat than can be afforded. Our model shows when and where control is most effective at different stages throughout a developing epidemic so that resources can be better targeted.”
“It can be tempting for authorities to start cutting down trees at the core of the infected area, but for this epidemic our research shows that this could be the worst thing to do, because susceptible vegetation will simply grow back and become infected again,” explains Cunniffe.