| Summary: | The aim of the study. Observations of the thermal regime of peat soils were carried out in three ecosystems of the complex Bakcharsky mire (56°50'N, 82°50'E): in an more drained raised bog with pine-shrub-Sphagnum community (ryam) and two lowered waterlogged ecosystems – sedge-Sphagnum poor fen (sedge mire) and shrub-cotton grass-Sphagnum marginal part of the poor fen adjacent to the ryam (cotton grass mire). Thermal regime of fibrist histosols was studied using temperature loggers – autonomous soil temperature meters AIPT (IMCES SB RAS, Tomsk). Loggers were installed into unflooded hummocks of 30–40 cm height in the ryam and sedge mire, and in the flooded leveled hollow of the cotton grass mire on June 26, 2012. The temperature was recorded until September 18, 2013, and in the cotton grass mire it was recorded until May 21, 2013, when the equipment failed due to high water table. The recording of temperature was carried out at depths of 2, 5, 10, 15, 20, 30, 40, 60, 80, 120, 160, 240cm once per hour. To assess the weather conditions during the study period, we used data on air temperature, precipitation and snow depth of the Bakchar weather station (http://rp5.ru). Main results. The average annual temperature in the peat soil of the ryam decreased from 3.9˚C in the surface layer to 2.7˚C at a depth of 160 cm and increased to 3.0˚C at a depth of 240 cm; in the sedge mire it increased from 3.4˚C in the surface layer to 6.7˚C at a depth of 160 cm and decreased to 6.2˚C at a depth of 240 cm. In the cotton grass mire, average temperature slightly increased from the surface to the deepest layers at 0.15˚C, averaging 4.7˚C. The annual temperature amplitude at a depth of 20 cm was slightly higher than 15˚C in the ryam and the cotton grass mire, which indicated soil climatic conditions as mild, and 21.6˚C in the sedge mire, which complied with the temperate continental soil climate. The average temperature during the warm period (June–September) in the sedge mire was 1.5–3.1˚C warmer than in the cotton grass mire. In ...
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