Forest fragmentation is ubiquitous, resulting in substantial differences in both micro-environmental conditions and biogeochemistry between the forest edge and interior. The majority of forests occur in fragmented landscapes, yet our understanding of forests and the role they play in carbon cycling is still predominantly based on intact ecosystems. Recent work shows increases in carbon uptake and storage at the forest edge, but this response is heterogeneous across climatic conditions. Individual study sites are often geographically limited and focus on limited environmental characteristics. The variability of the edge-to-interior gradient across land uses, forest types, and spatial configurations remains largely unknown. We have attempted to address these issues with a regional-scale approach. To examine macroscale variability, we combined the USFS’s Forest Inventory and Analysis database with 20,000 manually classified land cover maps across 20 states in the northeastern US to quantify the edge effect on tree growth dynamics. This study allowed us to measure the extent, variability, and mechanistic drivers of the altered forest carbon cycling.