Well, its here in the UK. However it arrived, the Government response was discracefully slow to ban imports. It seems it will probably wipe out most of the UK tree population. As an ecologist, what i would say is that we need to preserve the mature trees where we can if we are going to help one of our most loved trees to find immunity to the attack it is facing. No doubt the log merchants will be rubbing their hands together and felling every ash tree they can.
We need to find and manage the ones that are immune. We are yet to find out what the Forestry Commission and FERA are going to say on the use and transportation of diseased material, although there is no chance of containment of the disease.At least the dead and dying trees will provide great habitats for all kinds of wildlife. If you have an ash tree where it could cause a future hazard though it would be good sense to monitor any decline.
A tree that is healthy now wont immediately fall over after infection but branch drop may increase. If you are worried, get us to come and have a look – there are often other factors at play.