The mechanism of how soil carbon pools change when coniferous forests are converted into conifer-broadleaf mixed forests is poorly understood. In this study, the impact of additional carbon inputs on soil organic carbon mineralization and microbial communities was evaluated. In a microcosm incubation experiment, three types of 13C-labeled litter (Pinustabulaeformis (PT), Robiniapseudoacacia (RP), and a mixture of PT and RP (1:1, PR)) were added in to top (0–20 cm) and deep (60–80 cm) soil collected from a Chinese pine plantation. The priming effect (PE) and specific microbial groups involved in PE were studied. PT and RP addition to topsoil induced a negative PE. In deep soil, the decomposition rates of soil organic matter (SOM) after adding PT and mixture increased by 16.6% and 34.6% compared to those without litter. The addition of RP with a lower C:N ratio had a stronger negative PE than adding PT or mixture. Moreover, the PE in deep soil was more intense after all litter additions. In topsoil, the litter-derived carbon was mainly incorporated into 16:0, 18:1ω9c, and 18:1ω7c fatty acids. In conclusion, the addition of broadleaf litter into coniferous plantations might be beneficial for enhancing deep soil carbon stocks.
Correction: Effects of long-term fertilization on soil organic carbon mineralization and microbial community structure
