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The effect of anomalous temperature and precipitation on carbon dioxide fluxes in tundra and forest-tundra ecosystemsтезисы доклада
- Авторы: Gushchina Daria, Gorbarenko Elizaveta, Tarasova Maria, Zheleznova Irina, Emelianova Ekaterina, Gibadullin Ravil, Olchev Alexander
- Сборник: Proceedings of the JpGU Meeting 2025
- Тезисы
- Год издания: 2025
- Место издания: JpGU Chiba, Japan
- Аннотация: The development and functioning of landscapes in different regions of the world, especially at polar latitudes, may be significantly affected by the increased frequency of extreme weather events associated with modern climate change. The Northern Hemisphere tundra and forest-tundra landscapes are considered to be among the most vulnerable to changes in environmental conditions under a changing climate. Based on meteorological and CO2 flux data from the global FLUXNET network, the regional AmeriFlux and the European flux database cluster as well as the ERA5 reanalysis the spatial variability in the response of daily net ecosystem CO2 exchange (NEE) of Northern Hemisphere tundra and forest-tundra landscapes to anomalous temperature and precipitation events during the growing season was analyzed. A wide range of observed responses of NEE to extreme temperature and precipitation events was revealed depending on the geographic location and the type of landscape. While most previous studies documented the effect of stressed photosynthesis associated with abnormally high temperatures and consequently increased CO2 emission in polar ecosystems, we observed the similar response of CO2 only in ecosystems at the southern boundary of the polar region, where heat waves are more frequent. The opposite response was found in deciduous broadleaf forests, permanent wetlands and open shrublands, where CO2 uptake prevailed on 16-46% of the abnormally high temperature days. This effect can be attributed to the temperature regime of the polar region with not very high air temperatures, which do not lead to heat stress for the vegetation. The effect of the abnormally low temperature on the CO2 fluxes is that the positive NEE anomalies are larger than the negative ones, which is mostly associated with an increase in CO2 emissions. It was shown that the response of CO2 fluxes to anomalously high and low precipitation is rather similar regardless of the time scale (short-term or long-term response). The simultaneous response of CO2 fluxes to heavy precipitation is manifested in increased CO2 emissions to the atmosphere for most of the ecosystems studied. The cumulative effect is similar to the simultaneous one, i.e. heavy precipitation during the preceding 14 days mostly leads to positive NEE anomalies (higher CO2 emission). The prolonged precipitation deficit is accompanied by negative NEE anomalies in the majority of tundra and forest-tundra ecosystems considered, corresponding to increased CO2 uptake.This research was funded by the Russian Science Foundation, grant number 22–17−00073.
- Добавил в систему: Гущина Дарья Юрьевна