Author(s): Liang Wang; Huaidong Zhou; Chang Liu; Dongsheng Cheng; Jiapeng Wu
Linked Author(s): Chang Liu, Xiaosong Wang
Keywords: Greenhouse gas; Reed; Methane; Land/water; Wetlands; Eutrophication
Abstract: Methane (CH4) fluxes were monthly measured in a reed-dominated eutrophic wetland with static chamber method for one year. Results showed that there were significant spatial variations of CH4 emissions with pollution gradients in Baiyangidan wetland. Firstly, the severely polluted place (Station R) had about 20. 0 % higher CH4 emissions than the slighted polluted place (Q). From Station R to Station Q, the average CH4 emission value decreased from 1. 15±3. 20 mg/ (m2·h) to 0. 96±2. 97 mg/ (m2·h) and the highest soil TP value was found in Station R. Results indicated that increased nutrient contents would affect the decomposition rate of soil organic matter and the CH4 emission. In the longer term that would change the distribution of the soil carbon content. Secondly, water area was the source of CH4 and land area was the sink of CH4. From water area to land area, the CH4 emission gradually decreased. The downtrend of CH4 emissions was found in both stations. The highest value was found in water area R2 (14. 00 mg/ (m2·h) ) and Q1 (10. 73 mg/ (m2·h) ) and the lowest value was found in land area R4 (-3. 87 mg/ (m2·h) ) and Q3 (-7. 68 mg/ (m2·h) ). CH4 fluxes in the land/water ecotones also displayed a strong temporal variation and the freeze–thaw period was the important time for methane emission. The result showed that high nutrients input will stimulate the emission of CH4 in the reed-dominated wetlands, and the soil C content would be a limiting factor for CH4 emission in the Baiyangdian wetland.