Temperatures are warming rapidly in the northeastern U.S. Many tree species may expand their ranges north with warming temperatures, others may lose habitat along their southern range edges, and still others may endure a changing climate and retain current habitat. The timing of these changes and the ‘winner’ and ‘loser’ species remain uncertain. This study examines the early life-stage responses of 19 tree species in Acadia National Park to gain insight into which species may perform well under changing climatic conditions. We are using tree test beds at four sites (within Acadia National park along a natural climate gradient) to assess tree seedling performance.