In the mid 1970s an epidemic of the fungal infection, Dutch Elm disease, killed millions of Elm trees in England, and changed the British landscape forever. Witness talks to tree pathologist Dr John Gibbs who was at the centre of the attempt to save them.Picture: Dr John Gibbs and a colleague at the Forestry Commission pump fungicide into an elm tree in St James' Park in London during the fight against Dutch Elm disease. (Credit: Keystone/Getty Images)