ИСТИНА

Norilsk, the second largest city north of the Arctic circle, is home to an extensive nickel and copper smelting industry. Since the 1960s, the industrial development there, and specifically, air pollution, have caused extreme damage to the neighbouring ecosystems of tundra-taiga ecotone. However, as contemporary climate change stimulates “greening” in the high latitudes, we expect to see positive vegetation dynamics even in the most disturbed areas. The goal of this research was to identify recent vegetation changes in a large area surrounding Norilsk and attribute them to primary drivers. Using a time series of maximum summer NDVI calculated from Landsat satellite data for 1985-2020, we performed a Mann-Kendall trend analysis, which showed that a statistically significant, and indeed, the greatest increase of the vegetation index has happened in the previously most affected areas. A more detailed analysis of very high resolution imagery and subsequent classification demonstrated that whereas increases are mostly linked to the expansion of grasses, some tree and shrub recovery can also be noted. Our comparative analysis of emissions and meteorological data indicated that the observed greening can mostly be attributed to rising temperatures. Cumulative summer temperatures show a distinct relationship with maximum NDVI values, and their extremes typically correspond. However, the longterm changes are driven by a composition of factors, which was also investigated in this work.