How do we protect our native wildlife from invisible invaders like the ash dieback fungus.
Are ash trees coping with the spread of ash dieback in Britain? Adam Hart investigates.
Kathy Willis examines the origin and impact of Dutch elm disease across Europe.
Jonathan Freedland explores tree disease by charting Dutch Elm Disease from the 1920s.
Jolyon Jenkins investigates how Dutch Elm Disease swept through England in the mid-1960s.