Songlin Wu paper accepted by Environmental Science & Technology
Songlin Wu and coauthors report how microbial processing and Fe/Al-rich minerals jointly stabilize organic matter during four years of eco-engineered pedogenesis in iron ore tailings.
Authors: Songlin Wu, Zhen Li, Fang You, Wei Fu, Qi Feng, Guanghui Yu, Cheng-Wei Kao, Ting-Shan Chan, Baodong Chen, Gordon Southam, Longbin Huang
Journal: Environmental Science & Technology
This study examined microbial use, transformation, and stabilization of organic matter during eco-engineered soil formation in iron ore tailings through a four-year microcosm experiment. The work combined isotope labeling with 13C-glucose and 13C/15N-labeled spring wheat biomass, high-resolution Orbitrap mass spectrometry, and NanoSIMS to resolve long-term organic matter evolution at molecular and submicron scales.
The results show that both soluble organic inputs and plant biomass can form protein-, lipid-, and lignin-like molecules in tailings, with heterogeneous stabilization mainly mediated by Fe- and Al-rich minerals. In the 13C-glucose treatment, microbial 14N2 fixation generated microbial organic matter enriched in 13C and 14N.
In the 13C/15N-labeled biomass treatment, the study further revealed dynamic organic matter turnover: external 13C/15N signals gradually declined while new organic compounds derived from atmospheric 12C/14N emerged. The microbe- and mineral-mediated generation and stabilization of organic matter indicate the gradual development of in situ microbial C/N biogeochemical resilience in amended tailing systems.