Analysis of controlling factors of ecosystem-scale methane exchange in forests using isotope information

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K18718
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Forest science
• Research Institution: Kyoto University (2016, 2019); Osaka Prefecture University (2017-2018)
• Principal Investigator: Sakabe Ayaka 京都大学, 白眉センター, 特定助教 (40757936)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: メタン / 渦相関法 / 簡易渦集積法 / チャンバー法 / 温帯ヒノキ林 / 熱帯泥炭湿地林

Outline of Final Research Achievements

In a temperate cypress forest, the observed ecosystem-scale CH4 flux was small and close to the detection limit of the measurement system. However, CH4 uptake was observed in forest floor and higher CH4 emission was observed from the stem of Alnus japonica growing in riparian wetland than surrounding soils, and dynamic change in CH4 dynamics existed in the forest. Furthermore, these CH4 exchange rates were sensitive to the changes in environmental conditions. In peat swamp forest, a clear seasonal variation in ecosystem-scale CH4 exchange rates was detected in respond to changes in environmental conditions. Therefore, these environmental responses need to be incorporated into future models in order to predict how CH4 dynamics in forests will respond to climate change.

Free Research Field

森林における温室効果ガス交換量

Academic Significance and Societal Importance of the Research Achievements

森林は、水分不飽和な土壌でのメタン吸収のために、メタン吸収源として期待されている。しかし、実際の森林におけるメタン動態は複雑に放出と吸収が混在しており、その向き、大きさは環境条件によってダイナミックに変化することが示された。森林生態系スケールと森林内の構成要素ごとのメタン交換量の環境応答性を調べることによって、森林生態系がメタン収支に果たす役割の理解を進めることができた。