Reforestation for economic purposes but also for climate change mitigation will play an increasing role in the Anthropocene. Economic incentives are suspected to lead to the over-implementation of intensely managed, large-scale forest plantations. Their effects on biodiversity and contribution to biotic homogenization remain controversially discussed. Due to their long existence and strong economic promotion, we argue that the forest plantations of Chile are a unique cautionary tale in this regard. We assess biodiversity conditions in a large (>67,000 km2) study site on the basis of an exhaustive (195-plot) field assessment. It is shown that an entire landscape has been transformed from ecologically distinct natural forests to plantations with low ecological distinctiveness. We conclude that the Chilean experience may repeat in other countries and outline the importance of considering processes of biotic homogenization in addition to biodiversity losses when planning and implementing reforestation measures.