Forest edge effects in China are strongly shaped by human activities

Abstract Forest fragmentation has produced widespread edge zones, leading to declines in ecosystem functioning. Although human activities are the primary drivers of such ecological disturbance, how they modulate the depth and magnitude of edge effects remains insufficiently understood. Here we assessed edge effects in fragmented forests across China, a megadiversity nation with the largest afforested area and high deforestation risk. By 2023, nearly 88% of China’s forests are within 1 km of an edge, with roughly 95% of these edges adjoining anthropogenic land uses. Compared to natural forest edges, anthropogenic edges exhibit stronger edge effects on ecosystem productivity and its temporal stability, with productivity disrupted and stability declining markedly within ~210 m of edges. In contrast, natural edges show reduced productivity within ~100 m of edges but no detectable impact on ecosystem stability. These differences are primarily driven by canopy height, as well as changes in hydrological, thermal, and wind conditions. These findings underscore the importance of forest-edge conservation in China.