Methane fluxes along a permafrost hillslope gradient in Northcentral China

Abstract

Soil methane (CH4) uptake and emissions have significant impacts on global climate change. In this study, we focused on CH4 fluxes in a Larix gmelinii forest, the key vegetation type in the permafrost region of the Greater Xing’an Range of northeast China. We studied the relationship between soil CH4 fluxes and slope position during the growing season. The results indicate that slope position is one of the most important factors affecting soil CH4 fluxes in the Larix gmelinii forest. Soil CH4 uptake mainly occurred at the top and upper portion of the slope (-0.15 and -2.75 µmol · m-2 · hour-1, respectively). Soil CH4 emissions mainly occurred at the lower portion and bottom of the slope (1.01 and 2.29 µmol · m-2 · hour-1, respectively). The uptake of soil CH4 at the top and upper portion of the slope can offset much of the soil CH4 emissions from the lower portion and bottom of the slope in a Larix gmelinii forest.