Spruce-fir forests and associated bird species are recognized as some of the most vulnerable ecosystems and species to the impacts of climate change. This work capitalized on a rich suite of long-term data from these ecosystems to document recent trends in these forests and their associated bird species and developed tools for predicting their future abundance under climate change. Findings from this work indicate declining trends in the abundance of spruce-fir obligate birds, including Bicknell’s Thrush, across the Lake States and New England. In contrast, montane spruce-fir forests in the White and Green Mountains of New England exhibited patterns of increasing abundance, potentially due to their recovery from the negative impacts of historic land use and pollution. Despite these recent trends, long-term predictions of future abundance for the dominant species found in spruce-fir forests (black, red, and white spruce and balsam fir) indicated large declines in these species from across much of the northeastern United States by the year 2090. Several areas were recognized where these forests might persist, including high elevation portions of New Hampshire, New York, and Vermont and in large portions of northwestern Maine. An understanding of these future dynamics is critical for informing and prioritizing conservation efforts aimed at protecting these ecosystems and associated wildlife species under future climate change and speak to the importance of sustaining long-term monitoring efforts to assist these decisions.
