Methane emission from wetlands in Taiwan

To investigate methane emission from wetlands in Taiwan, soil properties, environmental conditions and methane emission were determined at three wetlands in northern Taiwan from September 1995 to April 1999. Soil pH values ranged from 6.15 to 7.80. Total organic carbon and total nitrogen contents were high in Kuan-du wetland and Kang-nan lake area, where the soils were sandy loam. In Kang-nan wetland, total organic carbon and total nitrogen contents were low and the soil was clay loam. Soil redox potential of Kuan-du wetland and Kang-nan lake area was lower than that of Kang-nan wetland. Atmospheric methane concentration was 0.8–2.7, 0.7–1.6 and 0.8–1.7 ppm (mg kg−1) in Kang-du wetland, Kang-nan wetland and Kang-nan lake area, respectively. Average methane emission rate was 1.82, 0.14 and 0.23 mg m−2 h−1 and annual methane emission was about 1.59×10−1, 1.23×10−2 and 2.02×10−2 ton ha−1, respectively. Annual methane emission from 11,896 ha of nine wetlands is estimated around 340 ton in Taiwan.