Methanotrophic food webs and carbon recycling in a subtrophic lake

2015 Fiscal Year Final Research Report

• Project/Area Number: 24405007
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 海外学術
• Research Field: Ecology/Environment
• Research Institution: Research Institute for Humanity and Nature (2014-2015); Kyoto University (2012-2013)
• Principal Investigator: OKUDA Noboru 総合地球環境学研究所, 研究部, 准教授 (30380281)
• Co-Investigator(Kenkyū-buntansha): KOJIMA Hisaya 北海道大学, 低温科学研究所, 助教 (70400009)
• Co-Investigator(Renkei-kenkyūsha): FUKUI Manabu 北海道大学, 低温科学研究所, 教授 (60305414) ; Tayasu Ichiro 総合地球環境学研究所, 研究部, 教授 (80353449) ; NAKANO Shin-ichi 京都大学, 生態学研究センター, 教授 (50270723)
• Research Collaborator: ITOH Masayuki 京都大学, 東南アジア研究所, 助教 ; KOBAYASHI Yuki 山口大学, 大学院医学系研究科, 講師 ; FUJIBAYASHI Megumu 秋田県立大学, 生物資源科学部, 助教 ; SHIAH Fuh-Kwo 中央研究院, 環境変遷研究中心, 研究員 ; HSIEH Chih-hao 國立台灣大學, 海洋研究所, 副教授 ; MIKI Takeshi 國立台灣大學, 海洋研究所, 副教授 ; HO Pei-Chi 中央研究院, 環境変遷研究中心, 大学院生 ; CHANG Chun-Wei 中央研究院, 環境変遷研究中心, 大学院生
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: メタン酸化細菌 / メタン栄養食物網 / 炭素リサイクル / 嫌気的メタン酸化 / NC10 / 安定同位体混合モデル / 脂肪酸分析 / 反応-拡散-移流モデル

Outline of Final Research Achievements

Recent studies suggest that freshwaters are the primary source of atmospheric methane emitted from natural ecosystems. Methane oxidizing bacteria (MOB) which assimilate dissolved methane aerobically or anaerobically have great impacts on methane cycling in freshwater ecosystems. Methanotrophic food webs (MFWs), in which methane-derived carbon is trophically transferred through the MOB and embedded within a food web, serve as a carbon recycling unit in lake ecosystems. In a deep subtropical Fei-Tsui Reservoir which is located in Taipei, methane profiles and MOB community composition showed characteristics intermediate between subtropical monomictic and tropical meromictic lakes. Our four-year monitoring revealed that typhoon-induced disturbance of thermal stratification and the subsequent decrease in profundal methane storage due to methane oxidation can be the primary limno-physical mechanism to affect the relative contribution of MFWs to the overall trophic carbon flows.

Free Research Field

生態学