Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (2): 131-143.DOI: 10.17521/cjpe.2020.0292

Special Issue: 生态系统碳水能量通量

• Research Articles • Previous Articles     Next Articles

Characteristics and environmental factors controlling methane emission from a Sphagnum bog with different plant cover types in a subalpine area, southwest of Hubei, China

MOU Li, WU Lin*(), LIU Xue-Fei, LI Xiao-Ling, WANG Han, WU Hao, YU Yu-Rong, DU Sheng-Lan   

  1. Biological Resources Protection and Utilization of the Key Laboratory of Hubei Province, School of Forestry and Horticulture, Hubei Minzu University, Enshi, Hubei 445000, China
  • Received:2020-08-27 Accepted:2020-12-12 Online:2021-02-20 Published:2021-02-07
  • Contact: WU Lin
  • Supported by:
    National Natural Science Foundation of China(41867042)


Aims Wetlands are important sources of atmospheric methane (CH4), but there are few reports on the CH4 emissions of subtropical and subalpine wetlands. In particular, the accurate estimation of CH4 emissions from plots with different types of plant cover and the controlling environmental factors are not clear. The objective of this study is to study characteristics and influencing factors of CH4 emission fluxes from a Sphagnum bog with different plant cover types in a subalpine area, southwest of Hubei Province.
Methods A Sphagnum bog in the subalpine area in southwest of Hubei Province was selected, and CH4emission fluxes were measured in the Sphagnum bog with three types of plant cover using closed static chamber and gas chromatography method from November 2018 to October 2019. Simultaneously, air temperature, soil temperature of 5 cm depth, and groundwater level were recorded.
Important findings (1) Under sunlight, the CH4-C fluxes from the bare land plot (B), the Sphagnum paluster plot (S), and the Polytrichum commune plot (P) varied throughout the year within the following ranges: 0.012- 1.372, 0.022-1.474 and 0.027-3.385 mg·m-2·h-1, respectively; under shading treatment, the variation range of CH4-C flux throughout the year from B, S and P plots were 0.012-1.372, 0.009-1.839 and 0.017-2.484 mg·m-2·h-1, respectively, indicating CH4emission sources for all types. At the same time, for all plant cover types, CH4 emissions under sunlight conditions were slightly higher than those under dark conditions, but the difference was not significant. (2) For all plant cover types, CH4 emissions showed obvious seasonal variations, with the order of summer > autumn > spring > winter; and summer emissions were significantly greater than emissions in other seasons, accounting for about 57% to 84% of the annual cumulative flux. This study found that the flux of CH4 emission was highly related to air temperature and soil temperature of 5 cm depth showing exponential relationships, which indicated that temperature is the main environment factor affecting the temporal variations of CH4 emission from the Sphagnum bog. (3) Plant cover types significantly affected CH4 emissions from theSphagnum bog. The annual average and cumulative CH4 emissions from the three cover types were in the order of: P > S > B. P plot showed significantly higher emission than B plot. This study found a significant correlation between vegetation types and CH4 emissions, indicating that plant cover type is the main influencing factor of the spatial variations of CH4 emissions from the Sphagnum bog. (4) CH4 emissions were not significantly related to the groundwater levels. This study further enriched the mechanisms of CH4 emission in the Sphagnum bog and provided basic data for regional carbon cycling.

Key words: subtropical, vegetation type, marshland, methane emission