Soil respiration in paludified forests of European Russia

Abstract

Soil respiration studies in paludified forests of the European part of Russia are quite rare in comparison with those of open peat bogs, which make long-term observations in this region highly relevant. In this study, soil CO₂ emissions were measured by the close chamber method in different microlandscapes of paludified forests. For four summer seasons with different environments, soil respiration ranged from 1078 to 248 mg CO₂ m⁻² h⁻¹ in a paludified spruce forest site with coarse woody debris to 659–820 mg CO₂ m⁻² h⁻¹ in a paludified boggy pine forest. The most intensive soil respiration was observed during the hot summer of 2013 and the lowest in the hot and humid summer of 2016. Annual total soil CO₂ emissions in paludified forests in 2015–2016 were approximately 2000–3000 g CO₂ m⁻². During the year, the lowest CO₂ emission values were observed from November to April (14–84 mg CO₂ m⁻² h⁻¹) and the maximum were in July and August (522–1205 mg CO₂ m⁻² h⁻¹). The contributions of CO₂ emissions in the cold November–April period were 6–8.5%. The impacts of temperature on soil respiration were higher (r² = 0.45–0.57) than those of groundwater levels (r² = 0.17–0.49). Soil respiration in the paludified spruce forest and in the pine bog generally were higher than emissions from ecosystems with similar hydrothermal conditions in the boreal zone.