11:00 〜 13:00
[ACG39-P01] 中国地方の森林土壌におけるメタン吸収速度の空間変動要因
キーワード：メタン、チャンバー、土壌水分、空間変動、火山灰土壌
Forest soil is an important sink of atmospheric methane (CH4) 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 CH4 flux and environmental parameters in forests in Western Honshu to examine the dominant factors for spatial variation of soil CH4 uptake rate.
Measurements were conducted in late November in 2021 in five forest sites (a Japanese cedar forest site, a deciduous broad-leaved forest site, a beech forest site, a mixed forest site, and a red pine forest site) in research forests that belong to Tottori University. PVC collars (30 cm inner diameter, 4 cm depth, n = 15 to 20) were set in measurement points in each forest site one day before measurement. In those measurement points, we measured CH4 flux using a portable automated chamber measurement system consisting of two cylindrical aluminum chambers (30 cm in diameter, 30 cm tall) and a control box. At the same time, soil temperature and soil moisture at the depth of 0-5 cm were also measured near each measurement point.
There were significant negative relationships between soil moisture and soil CH4 uptake rate in the beech forest site and the red pine forest site. On the other hand, there was no significant relationship between soil moisture and soil CH4 uptake rate in the Japanese cedar forest site, the deciduous broad-leaved forest site, and the mixed forest site. From those results, it was suggested that heterogeneity of surface soil moisture can partly explain the spatial variation of soil CH4 uptake rate in some forest ecosystems, but we also need to consider other soil physicochemical and biological parameters for a better explanation for the variation.
Measurements were conducted in late November in 2021 in five forest sites (a Japanese cedar forest site, a deciduous broad-leaved forest site, a beech forest site, a mixed forest site, and a red pine forest site) in research forests that belong to Tottori University. PVC collars (30 cm inner diameter, 4 cm depth, n = 15 to 20) were set in measurement points in each forest site one day before measurement. In those measurement points, we measured CH4 flux using a portable automated chamber measurement system consisting of two cylindrical aluminum chambers (30 cm in diameter, 30 cm tall) and a control box. At the same time, soil temperature and soil moisture at the depth of 0-5 cm were also measured near each measurement point.
There were significant negative relationships between soil moisture and soil CH4 uptake rate in the beech forest site and the red pine forest site. On the other hand, there was no significant relationship between soil moisture and soil CH4 uptake rate in the Japanese cedar forest site, the deciduous broad-leaved forest site, and the mixed forest site. From those results, it was suggested that heterogeneity of surface soil moisture can partly explain the spatial variation of soil CH4 uptake rate in some forest ecosystems, but we also need to consider other soil physicochemical and biological parameters for a better explanation for the variation.