Biodiv Sci ›› 2023, Vol. 31 ›› Issue (3): 22600.  DOI: 10.17520/biods.2022600

Special Issue: 土壤生物与土壤健康

• Original Papers: Plant Diversity • Previous Articles    

Lower water table increase shrub plant diversity and biomass but decrease soil organic carbon content: A case study of oligotrophic peatland in the Southwestern Hubei Province

Hao Wu1,2, Yurong Yu1,2, Jiayu Wang1,2, Yuanbo Zhao1,2, Yafei Gao1,2, Xiaoling Li2,3, Guijun Bu1,2, Dan Xue4, Lin Wu1,2,*()   

  1. 1 Hubei Key Laboratory of Biological Resources Conservation and Utilization, Enshi, Hubei 445000
    2 College of Forestry and Horticulture, Hubei Minzu University, Enshi, Hubei 445000
    3 Institute of Chinese Medicinal Materials, Hubei Academy of Agricultural Sciences, Enshi, Hubei 445000
    4 Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041
  • Received:2022-10-24 Accepted:2023-01-16 Online:2023-03-20 Published:2023-03-20
  • Contact: Lin Wu


Aim: The change of water table level has an obvious causative effect on the vegetation composition and diversity of peatlands, which may profoundly change the carbon sequestration potential of peatlands. However, the exact responses of the diversity of vegetation and soil organic carbon in peatland have to water table fluctuations are still controversial. In addition, there are few reports on the effects of water table level on plant diversity, biomass and soil organic carbon in oligotrophic peatlands in subtropical regions.

Methods: Soil organic carbon content, species diversity and vegetation biomass of different groundwater levels were compared by one-way ANOVA. Significant difference in species diversity and biomass of plant community were analyzed by LSD multiple comparison method (P = 0.05). Linear correlation analysis was used to compare the correlation among water level, oxygen content, Sphagnum moss and shrub biomass.

Results: (1) With a decrease in level of the water table, soil water content, soil organic carbon content and polyphenol content all decreased significantly, while dissolved oxygen increased significantly (P < 0.05). Moreover, soil organic carbon at the low-water table (-20 cm) was 72% of that at the high-water table (-4 cm). (2) Water table significantly changed the plant species composition of oligotrophic peatland in the Southwestern Hubei Province. With a decrease in level of the water table, the number of shrub species increased, and the shallow-rooted Ericaceae and Rosaceae were the dominant shrubs. (3) Overall, shrub diversity showed a significant increase with the decrease of water table (P < 0.05), while herbaceous diversity showed no significant change. (4) Water table had no significant effect on the total aboveground biomass of vegetation. However, with the decrease of water table, shrub biomass (P < 0.01) and herbaceous biomass (P < 0.05) significantly increased, while moss biomass decreased.

Conclusion: This study shows that a higher water table is a key factor to maintain soil organic carbon content in oligotrophic peatlands in the Southwestern Hubei Province, and the increase of vascular plant diversity does not increase the carbon sequestration potential of the peatlands.

Key words: Sphagnum peatland, water table, plant diversity, biomass, soil organic carbon