Spruce dominated forests undoubtedly represent one of the conservation ironies of the 21st century in the UK. These introduced tree species are planted extensively in commercial forestry and now offer a refuge to the endangered native Eurasian red squirrel (Sciurus vulgaris) in the face of competition from the introduced North American grey squirrel (S. carolinensis). The present chapter provides a concise historical overview of red squirrel population decline within the UK, describes the respective ecology and competitive interactions of both red and grey squirrels and the subsequent evolution of current conservation strategies. The importance of spruce dominated forests in the conservation of red squirrels is critically reviewed; population dynamics and habitat use are explored with particular focus upon patterns of tree seed availability, and the integration of squirrel conservation with parallel commercial forest management targets are described. Knowledge gaps in the proactive management of remnant red squirrel populations are presented, and we explore the potential impact of emerging disease threats to both squirrels and UK forest ecosystems.