Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (3): 434-446.DOI: 10.17521/cjpe.2021.0486

Special Issue: 微生物生态学

• Research Articles • Previous Articles    

Response of soil CO2 and CH4 emissions to changes in moisture and salinity at a typical coastal salt marsh of Yellow River Delta

LI Xue1,3,4, DONG Jie3, HAN Guang-Xuan1,2, ZHANG Qi-Qi1, XIE Bao-Hua1,2, LI Pei-Guang1,2, ZHAO Ming-Liang1,2, CHEN Ke-Long4, SONG Wei-Min1,2,*()   

  1. 1Key Laboratory of Coastal Environmental Processes and Ecological Restoration, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China
    2Yellow River Delta Field Observation and Research Station of Coastal Wetland Ecosystem, Chinese Academy of Sciences, Dongying, Shandong 257000, China
    3School of Geography and Environment, Liaocheng University, Liaocheng, Shandong 252000, China
    4School of Geography Science, Qinghai Normal University, Xining 810000, China
  • Received:2021-12-20 Accepted:2022-05-20 Online:2023-03-20 Published:2022-05-21
  • Contact: SONG Wei-Min
  • Supported by:
    NSFC-Shandong Union Project(U1906220);National Natural Science Foundation of China(41706097);National Key R&D Program of China(2019YFD0900703)


Aims Globally, coastal salt marshes have been considered as major blue carbon sinks and contributors for climate change mitigation. Understanding the effects of soil moisture and salinity on soil CO2and CH4 emissions will advance better understand of long-term storage of soil carbon in coastal salt marshes.

Methods We conducted a simulation experiment with a gradient of water treatments (25%, 50%, 75% and 100% soil saturated water content) and salt treatments (9 g·kg-1and 18 g·kg-1). And we investigated soil carbon mineralization rates, soil properties, microbial biomass and community structure of typical salt marsh soils in the Yellow River Delta.

Important findings We found that: (1) There was no interaction between soil moisture and salinity content on soil CO2, CH4 emissions and CH4:CO2, and soil CO2 emissions showed a unimodal curve along the soil moisture gradients and a significant decrease with increasing soil salinity content. The increased soil moisture significantly promoted soil CH4 emissions, but the increased soil salinity content significantly inhibited soil CH4emissions. (2) There was a weak significant interaction between moisture and salinity content on dissolved organic carbon (DOC). Under low water treatment, DOC content decreased with increasing soil salinity content, but increased under high water treatment. There was a significant positive relationship between soil CO2 emissions and DOC content. (3) Soil microbial biomass exhibited a trend of first increasing and then decreasing with the increasing soil moisture, while soil salinity content significantly decreased microbial biomass. There was a significant positive correlation of microbial biomass with CO2 and CH4 emissions. (4) Both soil moisture and salinity treatments modified soil microbial community structure. Soil moisture and salinity treatments significantly increased and decreased the number of bacteria and α diversity index, respectively. Both soil CO2 and CH4 emissions were positively correlated with the number of bacteria and α diversity index. The climate is gradually drying and warming in this region due to climate change. Therefore, we speculated that changes in microbial biomass and community structure, soil moisture and salinity content may have potentially profound effects on the carbon-sink function at coastal salt marsh.

Key words: soil water content, salinity, soil carbon mineralization, coastal salt marsh, Yellow River Delta, blue carbon