Permafrost peatlands are important pools of soil carbon. Soil organic carbon (SOC) mineralization and its temperature sensitivity in permafrost peatlands are crucial for predictions of soil carbon-climate feedback. However, little is known about the changes in SOC mineralization and its mechanism in response to environmental change in the permafrost peatlands of Northeastern China.
Dr. SONG Yanyu and Prof. SONG Changchun et al. from the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences collected seven permafrost peatland soils from Greater and Lesser Khingan Mountains in Northeastern China to investigate how the responses of microbes and labile substrates control the mineralization of SOC.
Results reveal that temperature and sampling sites affected the mineralization of SOC. Elevated temperatures significantly increased the rate of carbon mineralization across the peatland soils. The mean sensitivity of SOC mineralization to temperature (Q10 value) was 2.96.
The increase in substrate availability and microbial abundance in parallel with the increase in temperature is responsible for the high rates of decomposition of the organic carbon pools.
The results show that the mineralization of soil carbon positively correlated with the concentrations of soil dissolved organic carbon (DOC), NH4+-N, NO3？-N, as well as the abundances of bacteria, fungi, methanotrophs and nirK denitrifiers.
Moreover, the content of DOC positively correlated with the abundances of soil bacteria, methanotrophs and nirK denitrifiers, indicating that the influences of soil microbial abundances on carbon mineralization were strongly mediated by the availability of carbon substrates.
These findings provide novel insights into the effects of increasing temperatures on the relationship between microbial communities and labile substrates and their roles in carbon decomposition in permafrost peatlands.
The study entitled “Linking soil organic carbon mineralization with soil microbial and substrate properties under warming in permafrost peatlands of Northeastern China” has been published online in Catena.
This research was funded by the National Natural Science Foundation of China .
Contact:
SONG Yanyu
Northeast Institute of Geography and Agroecology
E-mail: songyanyu@iga.ac.cn
Web:http://english.iga.cas.cn/
