14:30 〜 14:45
[ACG39-04] NET CARBON EXCHANGE OF THE DESERT SHRUB ECOSYSTEM IN MONGOLIA
キーワード：Eddy Covariance, Greenhouse gas exchange, Gobi desert, Energy flux
Deserts with extreme conditions and sparse vegetation are about one-fifth of dryland areas. Therefore, in recent years, researchers have focused on understanding and determining the effects of deserts on the carbon cycle and carbon sequestration. However, it was reported that carbon exchange occurred in the wide range in desert areas. Thus, the effects of deserts on global warming and even their mitigating effects have been emphasized more.
Desert ecosystems, which are places where measurements are difficult due to reasons of extreme environmental conditions. This sometimes results in unrealistic or unexpected fluxes. In addition, studies have shown that abiotic activities in desert ecosystem cause carbon absorption in the nighttime and emission in the daytime. In addition, the effects of meteorological variables on NEE in the desert ecosystem are investigated. For this reason, in Gobi Desert, Tsogt-Ovoo in Mongolia, measurements with the eddy covariance method have been carried out with the Eddy Covariance system established by the Arid Land Research Center of Tottori University since March 2012 to analyze the carbon and energy exchange in the desert shrub ecosystem.
In this study, the energy fluxes such as latent heat flux (LE), sensible heat flux (H) and net radiation (Rn) and net ecosystem exchange determined by the Eddy Covariance method during a very low rainy growing season at the Tsogt-Ovoo location in the Gobi Desert of Mongolia will be presented.
The energy fluxes and net ecosystem exchange were determined in the growing period of 2019 (from 1 May and to 13 September). The total amount of precipitation measured in this period was extremely low (24 mm).
As a result, the daily latent heat flux value is extremely low as expected, with an average of about 23 W m-2 (about 23% of Rn). On the other hand, the daily mean sensible heat flux value is quite high (about 63 W m-2) due to dry conditions and constitutes about 63% of the daily mean Rn. During the measurement period, the daily average net carbon uptake was determined as about 0.4 gCm-2 and the total NEE was calculated as -55 gC m-2. Additionally, the highest monthly total carbon absorption determined in July. These values also include carbon absorption that occurs at night. However, if the nighttime carbon absorption of the surface is not considered, it causes to a less determination of the total NEE.
Desert ecosystems, which are places where measurements are difficult due to reasons of extreme environmental conditions. This sometimes results in unrealistic or unexpected fluxes. In addition, studies have shown that abiotic activities in desert ecosystem cause carbon absorption in the nighttime and emission in the daytime. In addition, the effects of meteorological variables on NEE in the desert ecosystem are investigated. For this reason, in Gobi Desert, Tsogt-Ovoo in Mongolia, measurements with the eddy covariance method have been carried out with the Eddy Covariance system established by the Arid Land Research Center of Tottori University since March 2012 to analyze the carbon and energy exchange in the desert shrub ecosystem.
In this study, the energy fluxes such as latent heat flux (LE), sensible heat flux (H) and net radiation (Rn) and net ecosystem exchange determined by the Eddy Covariance method during a very low rainy growing season at the Tsogt-Ovoo location in the Gobi Desert of Mongolia will be presented.
The energy fluxes and net ecosystem exchange were determined in the growing period of 2019 (from 1 May and to 13 September). The total amount of precipitation measured in this period was extremely low (24 mm).
As a result, the daily latent heat flux value is extremely low as expected, with an average of about 23 W m-2 (about 23% of Rn). On the other hand, the daily mean sensible heat flux value is quite high (about 63 W m-2) due to dry conditions and constitutes about 63% of the daily mean Rn. During the measurement period, the daily average net carbon uptake was determined as about 0.4 gCm-2 and the total NEE was calculated as -55 gC m-2. Additionally, the highest monthly total carbon absorption determined in July. These values also include carbon absorption that occurs at night. However, if the nighttime carbon absorption of the surface is not considered, it causes to a less determination of the total NEE.