Chin J Plant Ecol ›› 2018, Vol. 42 ›› Issue (7): 774-784.DOI: 10.17521/cjpe.2018.0104

Special Issue: 入侵生态学专辑

• Research Articles • Previous Articles     Next Articles

Effects of Spartina alterniflora invasion on soil organic carbon composition of mangrove wetland in Zhangjiang River Estuary

SUN Hui-Min1, JIANG Jiang1,*(), CUI Li-Na1, ZHANG Shui-Feng2, ZHANG Jin-Chi1   

  1. 1 Co-Innovation Center of Sustainable Forestry in Southern China, Key Laboratory of Soil and Water Conservation and Ecological Restoration in Jiangsu Province, Nanjing Forestry University, Nanjing 210037, China
    2 Nanjing Forest Police College, Nanjing 210023, China
  • Online:2018-07-20 Published:2018-09-26
  • Contact: Jiang JIANG
  • Supported by:
    Supported by the National Natural Science Foundation of China(41701225);the Natural Science Foundation of Jiangsu Province (BK20170920), and the Postgraduate Research & Practice Innovation Program of Jiangsu Province(KYCX17_0854)


Aims The composition of soil organic carbon has been changed significantly in mangrove ecosystems due to the invasion of Spartina alterniflora in recent years. However, few studies were reported on functional groups of soil organic carbon in the two communities. The object of this study was to understand the differences in soil carbon pool and organic carbon functional group characteristics in mangrove community and S. alterniflora community of Zhangjiang Mangrove Nature Reserve in Fujian Province.

Methods We used the method of “space for time” to study the changes of soil carbon composition following the invasion of S. alterniflora. Three transects were selected from landward to seaward in the wetland of Zhangjiang Mangrove Nature Reserve in Fujian Province, with three sampling sites in each transect: mangrove community (MC), transitional community (TC), and S. alterniflora community (SC). We sampled three plots in each site for replicates. Soil samples from five soil layers at 0-100 cm were collected to analyze the characteristics of total organic carbon (TOC), particulate organic carbon (POC) and dissolve organic carbon (DOC). Nuclear magnetic resonance (NMR) spectroscopy was used to analyze the functional group characteristics for surface (0-15 cm) and deep layers (75-100 cm).

Important findings We found that: (1) soil organic carbon decreased from MC to SC, with TOC and POC following the pattern of MC > TC > SC. However, the DOC did not show a clear trend. (2) The functional groups of soil organic carbon in all vegetation types were mainly alkyl carbon and alkoxy carbon, followed by aromatic carbon and carbonyl carbon. In the surface soil 0-15 cm, the alkyl carbon and alkoxy carbon showed an increasing trend from MC to SC. The aromatic carbon and phenolic carbon decreased from MC to SC. In the deep layer of 75-100 cm soil, however, soil organic carbon composition showed no significant difference among the three communities. (3) In the surface 0-15 cm soil, alkyl carbon/alkoxy carbon showed the following pattern: SC > MC > TC; SC has the least aromaticity; hydrophobic carbon/hydrophilic carbon showed no significant difference; aliphatic carbon/aromatic carbon showed larger values in SC than in MC and TC. At the depth of 75-100 cm, there were no significant differences for all the ratios. In summary, the carbon storage of MC was higher than that of SC. The decomposition rate of soil organic carbon of SC in surface soil layer was higher than that of MC, indicating more complex organic carbon in MC. The deep layer carbon pool was more stable and less affected by vegetation type. The results indicated that S. alterniflora would reduce soil carbon storage after invading mangroves, as well as changing the composition of soil organic carbon functional groups. The molecular structure of soil organic carbon in SC was simpler than MC, and the degree of decomposition was greater in SC than MC.

Key words: Spartina alterniflora, mangrove, organic carbon functional group, nuclear magnetic resonance