Wilderness Quality, Habitat Connectivity, and the Effectiveness of Protected Areas Diminish as Human Activities Intensify

Intact and connected wilderness areas are vital for biodiversity conservation. The Qinghai–Tibet Plateau (QTP) hosts some of the world's most unique ecosystems. Yet, increased economic development across the QTP raises concerns about the potential negative effects of increased human pressure on the stability of this unique biodiversity hotspot. In this study, we assessed the impacts of human activities on wilderness quality, habitat connectivity, and the effectiveness of protected areas across the QTP from 2000 to 2020. During this period, wilderness areas experienced a 41.08% reduction in large, intact patches, with a notable decline in quality, particularly in the eastern region of the QTP. Habitat connectivity decreased over time, and the cost of animal migration increased, with the most striking changes in areas with the highest initial wilderness quality. Economic growth and infrastructure development had strong negative impacts on the effectiveness of protected areas, with experimental protected areas declining faster than non-protected areas during periods of high infrastructure expansion. These emergent trend highlights the significant impact of increasing human pressure on animal migration and underscore the need for adaptive management and careful monitoring to ensure protected areas effectively prevent habitat fragmentation and support animal migration across global biodiversity hotspots.