13:45 〜 15:15
[MIS01-P02] Impact of extreme weather conditions on carbon dioxide fluxes in Northern Eurasian forests
キーワード：extreme weather conditions, carbon dioxide fluxes, Northern Eurasia
Modern climate change is accompanied by a dramatic increase in global temperature, changes in precipitation patterns and growth in the frequency and severity of extreme weather events. All these factors may obviously result in changes of the forest functioning, rates of evapotranspiration, carbon dioxide uptake and release. How the different forest ecosystems response to anomalous weather conditions is not known yet and it requires multifaceted experimental and modeling studies.
The main goal of the study to analyze the possible effects of extreme weather conditions on spatial and temporal variability of carbon dioxide fluxes within the temperate and boreal forest zones of Northern Eurasia. The ERA5 reanalysis data on the air temperature and precipitation were used to derive the spatial and temporal variability of weather conditions. The FLUXNET data set was used to obtain long-term data on carbon dioxide fluxes for various forest ecosystems in Northern Eurasia.
Extreme air temperature and precipitation thresholds were determined in terms of their impact on carbon dioxide fluxes. The threshold definition is based on the probability distribution (exceeding the 95% or 90% quantile) or on the exceeding of the standard deviation of the analyzed time series.
The results showed a significant effect of positive and negative temperature anomalies as well as a lack of precipitation on the carbon dioxide uptake and release by forest ecosystems. At the same time, the sign of the carbon dioxide flux anomaly associated to the same extreme weather conditions (for example, extreme high temperature) may vary within seasonal cycle and between the different forest ecosystems. Similar forest ecosystems in different geographic regions may respond differently to the same extreme weather conditions mainly due to differences in forest structure, plant biophysical properties and soil properties.
This study was supported by the Russian Science Foundation, grant number 22–17−00073.
The main goal of the study to analyze the possible effects of extreme weather conditions on spatial and temporal variability of carbon dioxide fluxes within the temperate and boreal forest zones of Northern Eurasia. The ERA5 reanalysis data on the air temperature and precipitation were used to derive the spatial and temporal variability of weather conditions. The FLUXNET data set was used to obtain long-term data on carbon dioxide fluxes for various forest ecosystems in Northern Eurasia.
Extreme air temperature and precipitation thresholds were determined in terms of their impact on carbon dioxide fluxes. The threshold definition is based on the probability distribution (exceeding the 95% or 90% quantile) or on the exceeding of the standard deviation of the analyzed time series.
The results showed a significant effect of positive and negative temperature anomalies as well as a lack of precipitation on the carbon dioxide uptake and release by forest ecosystems. At the same time, the sign of the carbon dioxide flux anomaly associated to the same extreme weather conditions (for example, extreme high temperature) may vary within seasonal cycle and between the different forest ecosystems. Similar forest ecosystems in different geographic regions may respond differently to the same extreme weather conditions mainly due to differences in forest structure, plant biophysical properties and soil properties.
This study was supported by the Russian Science Foundation, grant number 22–17−00073.