Abstract:

Aims The objective was to investigate the respiration rate of snowpack soil in relation to temperature in the alpine tundra community of Sanguisorba sitchensis (= S. stipulata) in the Changbai Mountain, northeastern China.

Methods Soil respiration under different temperatures was measured with an LI-8100 automated CO₂ flux system in the laboratory, and annual respiration was estimated based on current and presumed temperature scenarios.

Important findings Soil temperature under snowpack most of the year was around or over 0 °C, and the variation was less than 20 °C. Estimated respiration rates within 10 cm depth were 307.1 g C·m^-2·a^-1 at 2 036 m elevation and 270.9 g C·m^-2·a^-1 at 2 260 m. Because the snow cover was present for a long period, the length of which increased with elevation, winter respiration accounted for 42.5% at 2 036 m and 49.7% at 2 260 m. Under the scenario that the snow period decreases if annual temperature rises 1 °C, annual respiration would increase by 8% or 0.25 g C·kg^-1·a^-1 (22.65 g C·m^-2·a^-1), but winter respiration would decrease by 0.118 g C·kg^-1·a^-1 (10.81 g C·m^-2·a^-1).

Key words: alpine tundra, Sanguisorba sitchensis (= S. stipulata), snowpack, soil temperature, soil respiration