Organic soils can be CO 2 sinks in both drained and undrained hemiboreal peatland forests

作者：Aldis Butlers, Raija Laiho, Andis Lazdiņš, Thomas Schindler, Kaido Soosaar, Jyrki Jauhiainen, Arta Bārdule, Muhammad Kamil-Sardar, Ieva Līcīte, Valters Samariks, Andreas Haberl, Hanna Vahter, Dovilė Čiuldienė, Jani Anttila, Kęstutis Armolaitis · 发表于：Biogeosciences · 年份：2025 · DOI：10.5194/bg-22-4627-2025 · 被引用次数：5 · 研究领域：Peatlands and Wetlands Ecology、Botany and Plant Ecology Studies、Integrated Water Resources Management

Abstract. Drainage of organic soils is associated with increasing soil carbon dioxide (CO2) efflux, which is typically linked to losses in soil carbon (C) stock. In previous studies, drained organic forest soils have been reported as both CO2 sinks and CO2 sources depending on, e.g., soil nutrient and moisture regime. However, most of the earlier research was done in the boreal zone, and both the magnitude of CO2 efflux and the impact of soil moisture regime on soil C stock are likely to vary across different climatic conditions and ecosystems, depending further on vegetation. A 2-year study was conducted in hemiboreal forest stands with nutrient-rich organic soil (including current and former peatlands) and a range of dominant tree species (black alder, birch, Norway spruce, Scots pine) in the Baltic states (Estonia (EE), Latvia (LV), Lithuania (LT)). In this study, we analyzed the CO2 balance of organic soil in drained (19) and undrained (7) sites. To assess the CO2 balance, soil respiration was measured along with the evaluation of CO2 influx into the soil through aboveground (aGV) and belowground (bGV) litter. To characterize the sites and factors influencing the CO2 fluxes, we analyzed soil temperature, soil water table level (WTL), and physical and chemical parameters of soil and soil water. Irrespective of drainage status, the soils functioned as both CO2 sinks and CO2 sources. On average, a close-to-neutral soil CO2 balance (+0.45 ± 0.50 tCO2-Cha-1yr-1) was observed i...