Spatial Distribution of the Components of Carbon Cycle in Soils of Forest Ecosystems of the Northern, Middle, and Southern Taiga of Western Siberia

Abstract

In the course of studies in typical forest ecosystems of the northern, middle, and southern taiga of Western Siberia performed at the peak of the growing season, the spatial variation of soil CO2 emissions and their relationships with the content of extractable and microbial soil carbon and soil hydrothermic parameters were estimated. The studied parameters of the soil carbon cycle are characterized by the high spatial variability in all the studied ecosystems. This fact indicates the need for a detailed investigation of the greenhouse gas soil emission in all ecosystems typical of a given natural zone. There is a statistically significant difference between the soils of the green-moss pine forests and the soils of the lichen pine forest of the northern taiga. In the green-moss pine forest, the carbon content of microbial biomass is 1.5 times higher (195 ± 24 and 127 ± 16 mg C/kg soil, respectively), the content of extractable carbon is 4 times higher (157 ± 25 and 41 ± 5 mg C/kg of soil, respectively), and the CO2 emission is 1.7 times higher (324 ± 20 and 190 ± 10 mg CO2/(m2 h), respectively) than those in the lichen pine forest. In the northern taiga zone, carbon dioxide emissions from soils in the green-moss pine forests are largely determined by the soil temperature; the role of soil moisture is less significant. In the soils of lichen pine forests, the CO2 emission is mainly controlled by the content of extractable carbon. Significant factors influencing the soil СО2 emission in forest ecosystems of the taiga zone are the content of extractable and microbial carbon and hydrothermic parameters of the soils.