 This ecological reserve protects boreal, montane and alpine ecosystems in the Toulnustouc River ecological region (domain of the black spruce-fir and moss forest) and that of the Lac Marceau summits (domain of the black spruce fir forest).It also protects a site of exceptional geological interest since it is one of five Quebec sites characterized by a shock metamorphism structure.The relief of Île René-Levasseur is hilly.