ИСТИНА

Climate change is occurring more rapidly at high latitudes than in other regions of the world. Polar ecosystems are highly vulnerable to and significantly affected by such changes. The response of plants to changing environmental conditions is primarily manifested in changes in ecosystem and plant functioning, resulting in changes in water vapor (H2O) and carbon dioxide (CO2) fluxes. The main objective of the study was to analyze the seasonal variability of net ecosystem exchange (NEE) of СО2, sensible (Н) and latent (LE) heat fluxes in a subarctic palsa mire near Igarka and a northern taiga mature larch forest near Tura in north-central Siberia, and to assess the response of the fluxes in both ecosystems to variations in atmospheric parameters. The experimental data were collected using the eddy covariance method from 2019 to 2023. The results showed that both permafrost ecosystems consistently served as net sinks for atmospheric CO₂ over the growing season, regardless of significant year-to-year variations in meteorological conditions. Summer NEE varied from -62.9 to -120.2 gC m-2 in the Igarka palsa mire and from -63.5 to -83.6 gC m-2 in the Tura larch forest during the period 2019-2023. During prolonged summer periods of insufficient soil moisture, higher air temperatures and lack of precipitation, the palsa mire ecosystem is characterized by reduced NEE and GPP in contrast to the larch forest, which indicates a higher resilience potential of the larch forest to climatic influences than the palsa mire. H and LE fluxes also showed significant interannual variations, mainly determined by incoming solar radiation and precipitation variations. There is no significant decrease in LE during periods of low precipitation. The maximum rates of H and LE fluxes were observed in June and July at the maximum values of net radiation for both ecosystem types.