Soil Respiration Under a Short–Term Drought on the Example of Typical West Siberian Bogs (Middle Taiga)

Abstract

Cumulative (June–August) soil respiration (Rsoil(cum)), obtained based on field measurements and mathematical modeling, increased from wet areas of the oligotrophic bog to drained ones – “Hollow E.”, “Hollow Sh.” (hollows, dominated by Eriophorum vaginatum and Scheuchzeria palustris, respectively), “Open bog” (sphagnum bog with sparse low pine trees), “Ridge” (oligotrophic ridges covered with low pine trees), “Tall ryam” and “Ryam” (forested pine-shrub-sphagnum bog): 135 ± 2.3, 139 ± 2.4, 275 ± 7.8, 279 ± 7.5, 466 ± 16.4, 510 ± 18.5 g C/ (m2 season), respectively (mean ± std). An important factor of seasonal and annual variability of Rsoil was the water table level (WTL): the extremely low amount of precipitation (6 mm) that fell in July 2022 led to a sharp drop of WTL in August, an increase of the aerated soil zone. As result, total Rsoil(cum) over the summer in the studied biotopes increases by 29–54% compared to the same period in 2021. At the same time, the most intensive growth of Rsoil during the drop of the WTL was on the edge of the bog (“Tall ryam”, “Ryam” and “Open Bog”), in contrast to its central area.