Forest fragmentation increased in over half of global forests during years 2000-2020

Deforestation leads to habitat fragmentation, which adversely affects global biodiversity. Although some studies, using a separation-focused definition, have reported a decrease in fragmentation across 75% of the world's forests over recent decades, a comprehensive and ecologically relevant understanding of global fragmentation patterns remains lacking. In this study, we analyzed global fragmentation trends from 2000 to 2020, employing metrics that emphasize connectivity, aggregation, or separation. Connectivity-focused metrics reveal that 51% of global forests, particularly in tropical regions (58%), have undergone increased fragmentation—a rate nearly double that suggested by previous separation-focused metrics. This increase is corroborated by aggregation-focused metrics, which indicate heightened fragmentation in approximately 58% of forests worldwide and across all biomes. Further analysis attributes this escalation primarily to human activities, such as shifting agriculture and logging. Importantly, tropical protected areas have exhibited reductions in fragmentation by up to 82% compared to non-protected areas, underscoring the success of conservation efforts in these regions.