Abstrakts
Carbon (C) drainage of organic soils is associated with increasing soil carbon (C) efflux, which is typically linked to losses in soil C stock. In previous studies, drained organic forest soils have been reported as both C sinks and sources depending on, e.g., soil nutrient and moisture regime. However, most of the earlier research was done in boreal region, and both the magnitude of C 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 two-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, Latvia, Lithuania). In this study, we analysed the C balance of organic soil in drained (19) and undrained (7) sites. To assess the C balance, soil respiration was measured along with evaluation of C influx into the soil through aboveground and belowground litter. To characterize the sites and factors influencing the C fluxes, we analysed soil temperature, water table level, physical and chemical parameters of soil and soil water. On average, no changes in soil C stocks (0.45±0.50 t C ha−1 year−1) were observed in drained sites dominated by black alder, birch, or Norway spruce, while drained Scots pine sites showed soil C removals with a mean rate of 2.77±0.36 t C ha−1 year−1. In undrained birch- and spruce-dominated sites, soil functioned as mean C sink at 1.33±0.72 t C ha−1 year−1, while the undrained black alder stands showed an uncertain C balance of 1.12±2.47 t C ha−1 year−1. The variability in C balances were influenced by the nutrient-rich soil exhibiting a wide range of nutrient conditions and organic matter quality. Thus, indicating that soil macronutrient concentrations and pH can determine whether the soil functions as a C source or sink.
Pilns autoru saraksts
Butlers, A., Laiho, R., Lazdiņš, A., Schindler, T., Soosaar, K., Jauhiainen, J., Bārdule, A., Kamil-Sardar, M., Līcīte, I., Samariks, V., Haberl, A., Vahter, H., Čiuldienė, D., Anttila, J., & Armolaitis, K.
Publicēšanas informācija
2025, EGUsphere, 1-23
