Ecological shift in a remote alpine lake in inland Asia induced by European air pollutants

Abstract While ecological shifts in lakes within populated regions are often attributed to local or regional human activities, the impact of large-scale (e.g., hemispheric or global) anthropogenic forces on the ecology of extremely remote lakes remains unclear. Here we present a well-dated diatom record from Shuanghu Lake in the Altai Mountains, spanning the past 2400 years with a ~ 20-year resolution. This record, together with elemental data, vegetation cover reconstruction, and historical emission records from upwind Europe, enables us to examine the response of lake ecology to natural climate change and human activities. Our results indicate an ecological shift around 1870 CE, primarily due to lake acidification and eutrophication induced by the transport and deposition of European air pollutants. These findings suggest that even extremely remote lakes may experience ecological shifts driven by hemispheric-scale anthropogenic influences, providing valuable insights for ecologically sustainable development from a long-term and global perspective.