Disproportionate Changes in the CH4 Emissions of Six Water Table Levels in an Alpine Peatland

Abstract

The Zoige alpine peatlands are one of the highest and largest alpine peatlands in the world and play an important role in the global carbon cycle. Drainage is the main disturbance at Zoige, and the drawdown of the water table level changes CH4 emissions. There is still much uncertainty relating to how CH4 emissions respond to multiple water table levels. Here, we simulated six gradients (−30 cm, −20 cm, −10 cm, 0 cm, 10 cm, and 20 cm) of the water table level through a mesocosm manipulation experiment in the Zoige peatlands. The water table level had a significant effect on CH4 emissions. CH4 emissions did not change with water table levels from −30 cm to −10 cm, but significantly increased as the water table level increased above −10 cm. A significant log-linear relationship (R2 = 0.44, p < 0.001) was found between CH4 emissions and a water table level range from −10 to 20 cm. This study characterized the responses of CH4 emissions to multiple water table levels and provide additional data for accurately evaluating CH4 emissions. The results of this study also have several conservation implications for alpine peatlands.