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Climate change occurs more rapidly at high latitudes, making polar ecosystems highly vulnerable to environmental changes. Plants respond to these conditions by altering the fluxes of water vapor (H2O) and carbon dioxide (CO2). This study analyzed the seasonal variability of the Net Ecosystem Exchange (NEE) of CO2, as well as the sensible (H) and latent (LE) heat fluxes, in two ecosystems in north-central Siberia: a subarctic palsa mire near Igarka, and a mature larch forest near Tura. The flux responses to variations in atmospheric parameters were also assessed. Experimental data were collected from 2019 to 2023 using eddy covariance methods. The results showed that both permafrost ecosystems consistently served as net atmospheric CO2 sinks during the growing seasons, despite significant year-to-year meteorological variations. From 2019 to 2023, summer NEE ranged 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 summer periods characterized by prolonged insufficient soil moisture, higher air temperatures, and limited precipitation, the palsa mire exhibited reduced CO2 uptake (i.e., less negative NEE) and Gross Primary Production (GPP) compared to the larch forest. These results suggest that larch forests may be more resilient to climate change than palsa mires. This resilience is primarily linked to deep-rooted water access and conservative stomatal control in larch, whereas palsa mire vegetation depends strongly on surface moisture availability. H and LE fluxes exhibited significant interannual variations, primarily due to variations in incoming solar radiation and precipitation. No significant LE decrease occurred during periods of low precipitation in 2019 and 2020 when drought conditions were observed at both stations during the summer. Maximum H and LE flux rates occurred in June and July when net radiation values were at their maximum for both ecosystems. These findings underscore the urgent need for ecosystem-specific climate strategies, as differential resilience could significantly impact future carbon dynamics in the rapidly warming Arctic.

来源平台：ENVIRONMENTAL MONITORING AND ASSESSMENT