Tree Wardens get to know their local trees and are often the first point of contact from local residents who are concerned about the health of trees.
As of 2016 there are 12 tree diseases that have been identified by the Forestry Commission (FC) as having the potential to impact on our landscape, be that individual trees, native woodlands or commercial tree plantations. This is the link to the FC site.
Most of the tree diseases tree wardens might be aware of are caused by fungi. Ash Dieback is of most concern at the moment as it spreads across the UK. It is a fatal disease for Ash trees, first noted in this country in 2012 but has been spreading across Europe for the last twenty years. Ash seedlings, saplings, and young trees usually die in the first year of infection whereas more mature trees can take several years with gradual die back of the crown and larger branches.
The Woodland Trust have produced a good leaflet clearly setting out the identification of Ash Dieback disease.