Effect of Interannual Difference in Weather Conditions of the Growing Season on the СO2 Emission from the Soil Surface in the Middle-Taiga Cowberry–Lichen Pine Forest (Komi Republic)

Abstract

Data on the СО2 emission from the surface of iron-illuvial podzol (Albic Podzol) under an 84‑year-old cowberry–lichen pine forest of the middle taiga in the northeast of European Russia (the Komi Republic) during the growing seasons of 2014–2017 are discussed. Interannual differences in weather conditions were estimated from records of the Syktyvkar weather station. The emission of СО2 was measured by an infrared analyzer LI-COR 8100. In 2016, the duration of the growing season, mean air temperature, and the sums of effective (>5°С) and biologically active (>10°С) temperatures were 1.1–1.3 times higher than the long-term averages. Droughty seasons were absent in the studied period. The intensity of the CO2 emission correlated with the soil temperature at the depth of 10 cm; the correlation coefficient varied from 0.79 to 0.86 (p < 0.05). The temperature coefficient Q10 varied from 2.2 to 3.7; soil respiration at the temperature of 10°C, from 1.2 to 1.5 g С–СО2/(m2 24 h); at the temperature of 20°C, from 2.6 to 5.3 g С–СО2/(m2 24 h), the mean rate of soil respiration during the growing season, from 1.3 to 1.7 g С–СО2/(m2 24 h). The total emission of carbon in the form of CO2 from the surface of iron-illuvial podzol varied from 246 to 389 g/m2 with the maximum during the hot summer season of 2016.