A review of climate and landscape change effects on forest birds in a temperate mountain range

The combined effects of climate and landscape change are likely to be contributing to widespread and pervasive declines in forest bird populations. Individual species responses vary across climatic niches and habitat requirements, but bird communities and populations in montane systems may be particularly vulnerable to climate anomalies. Previous syntheses have reviewed evidence for impacts of climate change on bird species in general, in temperate regions and in Holarctic mountain ranges. Here, we propose that the Appalachian Mountains of eastern North America serve as an instructive case study due to their distinct combination of extensive temperate broadleaf forest cover, predominantly northeast–southwest orientation that bridges two major biomes and a bird assemblage that contains trailing‐edge populations of species that predominantly breed in the boreal forest. Our goal was to review the contemporary and potential future effects of both climate and land cover change on forest birds breeding in the Appalachian Mountains. Specifically, we focused on synthesizing documented and predicted changes in bird species distributions, populations and communities in response to changes in climate and land cover across this mountain range. We further compared our findings with trends from other mountain ranges across the world to assess commonalities and differences. Although there was limited literature from the Appalachian Mountains that incorporated both climate and land cover variables in models of forest bird responses, several results were consistent with studies from other montane systems, including vulnerability of cold‐associated species to warming temperatures and stronger effects predicted for future scenarios with higher greenhouse gas emissions. In addition, there were no prevailing trends that differed greatly from other mountain ranges, but potential extirpations of cold‐associated species varied along latitudinal gradients within the Appalachian Mountains region, and there was nuance in how changes in land cover and habitat conditions modified forest bird responses to climate change. We concluded our review by identifying key knowledge gaps, suggesting future directions for research and highlighting the conservation implications for forest birds in the Appalachian Mountains.