Soil respiration in larch and pine ecosystems of the Krasnoyarsk region (Russian Federation): a latitudinal comparative study

Abstract

Based on the long-term (12 years) data on soil respiration (SR) measurements in representative conifer forests of the Krasnoyarsk region (Central Siberia), we demonstrated specific characteristics of SR. The study sites located closely to Arctic Circle were related to different latitudes, including 56° N (SAE site, Krasnoyarsk), 60° N (ZOTTO site, Zotino), and 64° N (Tura site, Evenkia). Study sites were selected in forest ecosystems (> 41 years old) and represented a wide range of the climate, stand, permafrost availability, and soil types. However, the mean seasonal values of SR (mean ± SD) varied in a relatively narrow range from 2.11 ± 0.69 in the forest-steppe zone (SAE) to 2.82 ± 1.77 μmol CO2 m−2 s−1 in northern larch taiga (Tura). Nevertheless, a twofold difference in the duration of growing season among northern and southern locations results in a variation of total seasonal CO2 emissions (mean ± SD) from 216 ± 136 g C m−2 in larch stands of northern taiga to 369 ± 115 g C m−2 in larch stands of southern forest-steppe zone. Evaluation of the multiannual dynamics of SR over the past 1.5 decades (1995–2010) showed the escalation of SR in the permafrost larch stands (Tura) in 2005–2010. That has been coupled with the enhanced activity of the soil heterotrophic microbiota in 2007–2010. Our study highlights the importance of further monitoring of SR in permafrost Siberian ecosystems.