Factors of spatial variation in soil CH uptake rate in forests in Western Honshu

Teramoto, Munemasa*; Liang, N.*; Sun, L.*; Kondo, Toshiaki*; Koarashi, Jun   ; Atarashi-Andoh, Mariko  ; Takagi, Masahiro*; Yamanaka, Norikazu*; Hirano, Takashi*; Takagi, Kentaro*; Ishida, Sachinobu*; Ichii, Kazuhito*; Takahashi, Yoshiyuki*; Hu, R.*

Forest soil is an important sink of atmospheric methane (CH) in natural terrestrial ecosystems. However, there is still large uncertainty for the spatial variation of CH4 uptake rate in forest soils. In this study, we conducted field measurements for soil CH flux and environmental parameters in five forests in Western Honshu. There were significant negative relationships between soil moisture and soil CH uptake rate in the beech forest site and the red pine forest site, indicating that heterogeneity of soil moisture was one of the dominant factors for spatial variation of soil CH absorption in the sites. On the other hand, there was no significant relationship between soil moisture and soil CH uptake rate in the other three forests, suggesting that the dominant factors for the spatial variation of soil CH absorption might be different depending on the ecosystem.