Tree harvest and climate change can interact to have synergistic effects on tree species distribution changes. However, few studies have investigated the interactive effects of tree harvest and climate change on tree species distributions. We assessed the interactive effects of tree harvest and climate change on the distribution of 29 dominant tree species at 270 m resolution in the southern United States, while accounting for species demography, competition, urban growth and natural fire. We simulated tree species distribution changes to year 2100 using a coupled forest dynamic model (LANDIS PRO), ecosystem process model (LINKAGES) and urban growth model (SLEUTH). The distributions of 20 tree species contracted and nine species expanded within the region under climate change by end of 21st century. Distribution changes for all tree species were very slow and lagged behind the changes in potential distributions that were in equilibrium with new climatic conditions. Tree harvest and climate change interacted to affect species occurrences and colonization but not extinction. Occurrence and colonization were mainly affected by tree harvest and its interaction with climate change while extinctions were mainly affected by tree harvest and climate change. Synthesis and applications. Interactive effects of climate and tree harvest acted in the same direction as climate change effects on species occurrences, thereby accelerating climate change induced contraction or expansion of distributions. The overall interactive effects on species colonization were negative, specifically with positive interactive effects at leading edges of species ranges and negative interactive effects at trailing edges. Tree harvest generally did not interact with climate change to greatly facilitate or ameliorate species extinction. Our modelling results highlight the importance of considering disturbances and species demography (e.g. post‐harvest regeneration dynamics) when predicting changes in tree distributions.

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Birds and their habitats are facing unprecedented threats from a multitude of threats. Threats to birds, and consequently their population trajectories, vary both across space and among species groups, and greater knowledge of these patterns will help inform bird conservation and management. Here, we adapt existing methods to estimate continental bird population loss to a regional scale. Our objectives were to (1) identify patterns in regional population change (abundance) for 141 species of landbirds breeding in the Southeast; (2) compare these with continental patterns for the same suites of species, and (3) examine whether population–level changes in the Southeast suggest immediate, regional conservation actions. We found that landbird population losses were overall similar in the Southeast and across North America (−21%). Shrikes, nightjars, and swifts experienced the largest proportional losses among families in both regions. Birds associated with early seral and emergent wetland habitats experienced the greatest losses as did partial migrants and species listed on the Birds of Conservation Concern list for southeastern Bird Conservation Regions. Facultative aerial insectivores experienced the greatest losses in both regions, while obligate aerial insectivores increased in the Southeast in contrast to continental declines, due to rapid population growth in Cliff Swallows (Petrochelidon pyrrhonota). Within the Southeast, the greatest bird losses were in Peninsular Florida and Gulf Coastal Prairie, while the Mississippi Alluvial Valley Bird Conservation Region — where extensive reforestation efforts have been undertaken — had the smallest losses. We found clear differences in patterns of landbird population loss between the Southeastern United States and North America, as well as within the Southeast region. Results from these analyses should provide conservation agencies and partnerships with additional information and new perspectives to guide landscape–level planning and on–the–ground bird conservation delivery efforts to help bring back the nearly three billion birds lost across North America since 1970.