In 1980, the Irish state designated 19-hectares of woodland on the eastern slopes of Derryclare as a Statutory Nature Reserve called the Derryclare Nature Reserve (or Derryclare Wood by some sources). The broadleaf trees in the reserve are composed of Sessile Oak, with Rowan (Sorbus aucuparia), Downy Birch (Betula pubescens) and some Ash (Fraxinus excelsior) creating a canopy layer; there are well-developed lichen and fungus flora present. The fungal parasite, Hemigrapha astericus, a native of Australia and South America, was first recorded in the northern hemisphere in Derryclare Wood.