Trees are vital for biodiversity, yet many Irish species have declined, including the Wych Elm, devastated by Dutch elm disease. But four mature elms in Rathmines appear to have survived. Arboricultural Consultant Joe McConville is investigating whether their genetics could help restore elms across Ireland...

Derek Mooney and guests explore the natural world in all its forms. Listen live every Monday at 10pm on RTÉ Radio 1.