Tree Health event today 9th March, hosted by the Forestry Commission, to provide information on the risks that trees in London may soon be, or already are, subjected to.
Asian Longhorn Beetle (outbreak has already occurred in Kent in 2012)
3,800,000 trees could get affected with replacement cost of a staggering £23,000,000,000
Ash Dieback (already everywhere throughout the country) In London alone could kill a possible 374,195 ash trees. It is projected that it would cost £447,345,251 to replace the dead ash in London.
Plane Wilt, which currently plagues parts of continental Europe, its emergence and impact would lead to 121,000 plane trees being felled / dying and an attributed replacement cost of £351,623,660.
Don't forget, these are estimates for London alone. It doesn't take much imagination to see the effect it would have throughout the country.
With Ash Dieback I think we will see much more evidence of this in Calderdale this year, following many early signs in the valley last couple of years.