New insights into the methane emission processes from wetland ecosystems: A concerted activity of atmospheric chemistry and plant ecology researches

• Project/Area Number: 18H03356
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Kyoto University
• Principal Investigator: Takahashi Kenshi 京都大学, 生存圏研究所, 准教授 (10303596)
• Co-Investigator(Kenkyū-buntansha): 常田 岳志 国立研究開発法人農業・食品産業技術総合研究機構, 農業環境変動研究センター, 主任研究員 (20585856) ; 坂部 綾香 京都大学, 白眉センター, 特定助教 (40757936) ; 伊藤 雅之 兵庫県立大学, 環境人間学部, 准教授 (70456820) ; 小杉 緑子 京都大学, 農学研究科, 教授 (90293919)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥16,900,000 (Direct Cost: ¥13,000,000、Indirect Cost: ¥3,900,000); Fiscal Year 2020: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2019: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2018: ¥8,840,000 (Direct Cost: ¥6,800,000、Indirect Cost: ¥2,040,000)
• Keywords: メタン / 湿地生態系 / 温室効果ガス / レーザー分光法 / フラックス / 大気化学 / 植物生態学 / 温室効果気体 / 土壌微生物 / レーザー分光 / フラックス計測 / レーザー計測

Outline of Final Research Achievements

Using near-infrared laser spectroscopy, we have developed a technique for quantifying the amount of CH4 generated in a riparian wetland of a temperate forest in Shiga prefecture. In particular, our research aimed at estimating in detail the CH4 emission rate from the stem surface of Alnus japonica that is a major tree species in an anaerobic environment. Tree-mediated CH4 emission is a relatively new phenomenon that has received much attention in recent years. We successfully clarified seasonal to diurnal variations in CH4 emission rate from A. japonica. In order to clarify the factors that control the amount of emission, we performed chemical analysis of soil water in the rhizosphere and surface soils and measured environmental parameters such as soil temperature, air temperature, groundwater level and actinic short-wave radiation. A strong correlation was found between the concentration of CH4 dissolved in the soil water and the rate of CH4 emission from the stem surface.

Academic Significance and Societal Importance of the Research Achievements

メタンガスは二酸化炭素に次ぐ放射強制力を持つ重要な温室効果気体である．最近見つかったメタン発生源としての湿地性樹木に着目し，放出量を定量化するレーザー計測技術を開発するとともに，放出量の季節変動や気象要素に対する応答を明らかにした．大気中のメタンガス収支の精緻化に貢献する重要な成果である．

Research Products

• [Journal Article] Controlling factors of methane dynamics in tropical lakes of different depths (2021)
  • Author(s): Mendoza-Pascual, M. U., Itoh, M., Aguilar, J. I., Padilla, K.S.A.R., Papa, R. D. S., Okuda, N.
  • Journal Title: Journal of Geophysical Research- Biogeosciences Volume: 126 Issue: 4
  • DOI: 10.1029/2020jg005828
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] 湿地生態系からのメタン発生に関する最近の知見 (2021)
  • Author(s): 高橋 けんし
  • Organizer: 日本気象学会近畿支部会
• [Presentation] Emission of methane from the stems of several Japanese tree species: Variations between species and individuals, and within individuals (2021)
  • Author(s): D. Epron, A. Sakabe, K. Takahashi, M. Harada, T. Watanabe, and S. Asakawa
  • Organizer: The 68th Annual Meeting of the Ecological Society of Japan
  • Int'l Joint Research
• [Presentation] Study on methane fluxes from stem of cypress in an upland temperature forest (2021)
  • Author(s): Zhining Liu, Ayaka Sakabe, Yoshiko Kosugi
  • Organizer: 日本農業気象学会2021年全国大会
  • Int'l Joint Research
• [Presentation] 温帯林の湿地におけるハンノキ樹幹からのメタン放出の季節変動 (2020)
  • Author(s): 坂部綾香，高橋けんし，東若菜，伊藤雅之，小杉緑子
  • Organizer: 日本農業気象学会2020年大会
• [Presentation] Methane emission from woody stem and its potential impact on atmospheric methane budget (2019)
  • Author(s): K. Takahashi, A. Sakabe, M. Itoh, W. Azuma, M. Tateishi, M. Ataka, Y. Kosugi
  • Organizer: IGAC小委員会およびiLEAPS/IGAC-Japan合同研究集会
  • Invited
• [Presentation] 温帯林におけるハンノキ樹幹からのメタン放出に関する研究 (2019)
  • Author(s): 坂部綾香，高橋けんし，東若菜， 伊藤雅之，立石麻紀子，小杉緑子
  • Organizer: 日本農業気象学会2019年全国大会
• [Presentation] Application of laser spectrocopy techniques to atmospheric chemistry studies in a forest environment (2018)
  • Author(s): K. Takahashi
  • Organizer: International conference on tropical meteorology and atmospheric sciences (ICTMAS)
  • Int'l Joint Research
• [Presentation] Methane emission from the stems of Alnus japonica in riparian wetlands within a temperate forest catchment (2018)
  • Author(s): Kenshi Takahashi, Ayaka Sakabe, Masayuki Itoh, Wakana Azuma, Mioko Ataka, Makiko Tateishi, and Yoshiko Kosugi
  • Organizer: The 2018 joint 14 th iCACGP quadrennial symposium and 15 th IGAC science conference
  • Int'l Joint Research
• [Presentation] Estimating relative contribution of autotrophic respiration to soil respiration in permafrost region of Alaska, using 13C pulse labeling method (2018)
  • Author(s): A. L. Yoshikawa, M. Dannoura1, K. Yasue, T. Shirota, K. Takahashi, T. Morishita, T. Saito, R. Yamamoto, Y. Matsuura, K. Noguchi, C. Hossann, R. W. Ruess
  • Organizer: IBFRA18 (The cool forests conference)
  • Int'l Joint Research
• [Remarks] 京都大学生存圏研究所 大気圏環境情報分野 ホームページ
  • URL: http://www.rish.kyoto-u.ac.jp/laeia/members/tkenshi/index.html