Variations in the Aboveground Phytomass in Northern Eurasia in the 21st Century

Changes in the phytomass of the ecosystems of Northern Eurasia were traced based on the results of modeling and analysis of multispectral satellite imagery (MODIS archives 2000–2020). It was established that, since the end of the 20th century, an increase in reserves has been noted caused by climate change (an increase in the concentration of CO 2 , annual mean temperatures, etc.). Application of the GIS-information products based on the MODIS-projective vegetation cover (MODIS/006/MOD44B), evapotranspiration and the thermal field (MOD16A2), and biological production (MOD17A3HGF) allowed us to conduct retrospective modeling of the trend in the aboveground carbon reserves (tC/ha). It was revealed that in the years 2000–2020, a slight trend remained of an increase in the phytomass of forest ecosystems (1.2–6.0%), floodplain, and mountain meadows and shrubs (8.1–9.8%). In the last 17 years, a negative trend has been observed in treeless biomes: –6.0% in tundra, –9.0% in meadow and typical steppes, and –11.3% in deserted steppes. Multidirectional changes in carbon reserves of the aboveground phytomass of biomes, in addition to the internal (succession) and external (climate and anthropogenic transformation: forest felling, landscape fires, etc.) factors, are also due to the synergy of their action.