The seasonal dynamics of soil CO2 fluxes in Central Siberia
Anastasia V. Makhnykina1, Anatoly S. Prokushkin2, Sergey V. Verkhovets1 & Nataly N. Koshurnikova1
1Siberian Federal University, Krasnoyarsk, 660041, Russia 2V.N. Sukachev Institute of forest SB RAS, Krasnoyarsk, 660036, Russia
Studies on the role of soil processes are needed to quantify the large scale surface effluxes of greenhouse gases and to determine the effects of land use and land cover changes. The efflux of soil CO2 is highly sensitive to changes in surface temperature and relatively small changes in surface temperature may have a major influence on the magnitude of soil efflux. The potential increase in CO2 release from the soil caused by future elevated temperature may have a positive feedback effect on the atmospheric CO2 and global change.
In our study we compared the dynamic of soil CO2 fluxes from different types of underline surfaces for four different growing seasons (droughty, normal and overmoistened years). The research region was located in the middle taiga zone in Central Siberia (60° N, 90° E).
We found that the soil efflux is highly vary and depends on meteorological conditions of exact year. The soil temperature and soil moisture determined the magnitude of soil effluxes with relations depending on land cover of each site. The max fluctuations and variation of soil efflux were observed: in July – mid of August; in the mixed forest with the highest plant diversity. Analysis of Q10 is identified the efflux from the feathermoss pine forest controlled by moisture conditions higher than in lichen pine forest due to the distinction in the soil properties. The temperature is the main driving factor of the soil effluxes in the mixed forest and the max fluxes were similar in years with a comparatively high temperature and low precipitation level. The destroyed area was characterized by the lowest soil effluxes and we did not detect any changes in the dependence with soil temperature and soil moisture during the different years. The mean efflux for the whole measurement area is 197 mol CO2 m-2 for one growing season.