Abstract
Authors
MIYAMA Takafumi, HASHIMOTO Taro, KOMINAMI Yuji, NAKAGAWA Kenta, OKUMURA Motonori,TOHNO Susumu
Year
2010
Title
Temporal and spatial variations in CH
4 concentrations in a Japanese warm-temperate mixed forest
Journal
Journal of Agricultural Meteorology
Volume
66(1)
Page
1-9
DOI
doi:10.2480/agrmet.66.1.1
Keywords
CH
4 profile, Daily variation, Seasonal variation, Soil gas exchange
URL
http://www.jstage.jst.go.jp/article/agrmet/66/1/1/_pdf/-char/ja/
Abstract
To clarify the characteristics of the variation in methane (CH
4) concentrations in a warm-temperate mixed forest in Japan, we measured vertical profiles and daily and seasonal variations in CH
4 concentrations, and soil and foliage (
Quercus serrata) CH
4 fluxes. CH
4 concentrations increased dining rainy periods, and decreased in August. Almost constant CH
4 uptake was observed at the forest floor throughout the year, but no CH
4 flux was observed from the foliage. In the profile measurements, the CH
4 concentration was slightly higher at canopy height when friction velocity (u*) was lower than 0.3 m s
-1. These phenomena were observed on the same day at micrometeorological towers in ridge and valley positions. Variations in CH
4 concentrations increased in summer, around ground level, and at canopy height. These results suggest that certain large scale factors govern variations in CH
4 concentration around ground level and at canopy height. To understand the overall role of the forest in CH
4 circulation, more continuous measurements as close as possible to sinks and sources will be needed.
Site
YMS
Remarks