Chalara dieback of ash (Hymenoscyphus fraxineus) in Friston forest. East Sussex?

 At this time of year the beech trees in Friston forest cast a deep shade.  Sunlight was streaming into the wood behind the beech trees above.  What was causing this was a sorry sight for the Ash trees.
I imagine that it is caused by Chalara dieback of ash (Hymenoscyphus fraxineus)

For detailed info' see http://www.forestry.gov.uk/ashdieback