Dynamics of the CO2 Fluxes from the Soil Surface in Pine Forests in Central Siberia

Abstract

In forest ecosystems, the CO2 efflux from the soil may account for 40–80 % of the total amount of released CO2. Domination carbon breath losses over productivity may change the functional role of the ecosystem and transform it from a carbon sink to source. One of the most important field of study in soil respiration research is to identify a uniform methodology for measuring CO2 fluxes from the soil surface and its standardization. In our study, we assessed the investigation of the temporal and spatial dynamics of CO2 flux from the soil surface using the method based on the dynamic closed chambers in the middle taiga forests of Central Siberia. Soil respiration measurements were carried out during the growing season from June to October 2013. The period, when the soil respiration reached to maximum development – the second half of July to the end of August 2013. The ground cover substantially affected the value of soil respiration. The smallest value observed at the site without any plant cover – pp_sand (0.11–1.24 μmol CO2 m-2 s-1), which is 8 times lower than in the forested areas. The greatest values were attended at the site with mixed forest ranged from 2.31 to 8.41 μmol CO2 m-2 s-1. An important condition to obtain reliable results is the frequency of measurements. It was found that the measurements with a frequency of 5 or more times per month does not exceed the variation coefficient of 10 %, which indicates high reliability of the obtained values

Keywords

• LI-COR
• carbon cycle
• boreal forest
• soil respiration
• soil moisture
• measurements frequency
• LI-COR