Inishturk’s biodiversity is inseparable from its geodiversity — the rocks, soils, landforms and watercourses that shape the island. Four types of Ordovician bedrock influence soils and vegetation patterns, while Irish place names across the island preserve a close relationship between landscape, language and lived experience.

Following the last Ice Age, vegetation gradually returned, with juniper, birch and later woodland species such as hazel, pine, oak, holly and rowan. Over time, farming, grazing and peat cutting transformed the landscape, creating the grasslands and heathlands that characterise the island today. Royal Fern, a species with a history stretching back over 11,000 years, still survives on Inishturk.