Search Results 1-20 of 269

  • Soil carbon flux research in the Asian region: Review and future perspectives

    Liqing SHA , TERAMOTO Munemasa , Nam Jin NOH , HASHIMOTO Shoji , Meng YANG , Montri SANWANGSRI , Naishen LIANG

    … Soil respiration (<I>R</I><SUB>s</SUB>) is the largest flux of carbon dioxide (CO<SUB>2</SUB>) next to photosynthesis in terrestrial ecosystems. … As this region is characterised by highly diverse ecosystems, it is expected to experience the strong impact of ecosystem responses to global climate change. … This review focuses on five important aspects: 1) the historical methodology for soil C flux measurement; …

    Journal of Agricultural Meteorology 77(1), 24-51, 2021

    J-STAGE 

  • Recent advances in the understanding of ecosystem processes at eddy covariance CO<SUB>2</SUB> flux sites in East Asian forest ecosystems: a review

    Shih-Chieh CHANG , Taku M. SAITOH , SHIBATA Hideaki , Satoshi N. SUZUKI

    … To elucidate the dynamic features of carbon sequestration in ecosystems under changing climates and various disturbance regimes, researchers must understand key ecosystem processes, such as carbon allocation and partitioning, organic matter decomposition, and nutrient cycles, as well as plant functional traits. … flux sites in East Asia to clarify these ecosystem processes and attributes. …

    Journal of Agricultural Meteorology 77(1), 52-65, 2021

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  • Review and future perspective of AsiaFlux

    Guirui YU , HIRANO Takashi

    … AsiaFlux (http://www.asiaflux.net/) was established in 1999 as the Asian arm of FLUXNET, the worldwide flux network, to develop collaborative research and data sets on the cycles of carbon and water in key ecosystems in Asia, to organize workshops and training on current and related global change themes, and to cultivate next generation scientists to be informed leaders with skills and perspectives. … More than 100 flux observation towers were built in Asia, covering diverse terrestrial ecosystems. …

    Journal of Agricultural Meteorology 77(1), 1-1, 2021

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  • Terrestrial ecosystem model studies and their contributions to AsiaFlux

    ITO Akihiko , ICHII Kazuhito

    … This review summarizes the achievements of model studies conducted in Asia, a focal region in the changing Earth system, especially collaborative works with the regional flux measurement network, AsiaFlux. … Process-based biogeochemical models have been developed to simulate the carbon cycle, and their accuracy has been verified by comparing with carbon dioxide flux data. …

    Journal of Agricultural Meteorology 77(1), 81-95, 2021

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  • Climate change considerations are fundamental to management of deep‐sea resource extraction

    Lisa A. Levin , Chih‐Lin Wei , Daniel C. Dunn , Diva J. Amon , Oliver S. Ashford , William W. L. Cheung , Ana Colaço , Carlos Dominguez‐Carrió , Elva G. Escobar , Harriet R. Harden‐Davies , Jeffrey C. Drazen , Khaira Ismail , Daniel O. B. Jones , David E. Johnson , Jennifer T. Le , Franck Lejzerowicz , Satoshi Mitarai , Telmo Morato , Sandor Mulsow , Paul V. R. Snelgrove , Andrew K. Sweetman , Moriaki Yasuhara

    … Climate change manifestation in the ocean, through warming, oxygen loss, increasing acidification, and changing particulate organic carbon flux (one metric of altered food supply), is projected to affect most deep-ocean ecosystems concomitantly with increasing direct human disturbance. … Climate drivers will alter deep-sea biodiversity and associated ecosystem services, and may interact with disturbance from resource extraction activities or even climate geoengineering. …

    Global Change Biology 26(9), 4664-4678, 2020-07-06

    IR 

  • Terrestrial loads of dissolved organic matter drive inter-annual carbon flux in subtropical lakes during times of drought

    Chiu Chih-Yu , Jones John R. , Rusak James A. , Lin Hao-Chi , Nakayama Keisuke , Kratz Timothy K. , Liu Wen-Cheng , Tang Sen-Lin , Tsai Jeng-Wei

    … We investigated how contrasting summer and autumn precipitation can shape annual and inter-annual variation in ecosystem carbon (C) flux (gross primary production (GPP), ecosystem respiration (ER), and CO2 efflux) in two subtropical lakes differing substantially in trophic state and water color. … Reduced precipitation caused immediate and prolonged effects on C flux in both lakes. …

    Science of the Total Environment (717), 137052, 2020-05-15

    IR 

  • A mechanism for non-linear amplification of methane flux to the early Earth's atmosphere  [in Japanese]

    Akahori Aika , Watanabe Yasuto , Tajika Eiichi

    <p>初期地球の「暗い太陽」の条件下で温暖気候を実現するためには,メタン菌の活動によって生成されるメタンが重要な役割を演じていたのではないかと考えられている.Ozaki et al. (2018) は,大気光化学-海洋微生物生態系結合モデルを用いて太古代の地球大気に想定されるメタン濃度が実現可能な条件を検討した.そして,当時の主要な基礎生産者が水素資化光合成細菌と鉄酸化光合成細菌の共存 …

    Abstracts of Annual Meeting of the Geochemical Society of Japan 67(0), 68, 2020

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  • Characteristics of the relative sampling error and its application to flux aggregation in eddy covariance measurements

    Wonsik KIM , SEO Hyeongho , KOMORI Daisuke , Jaeil CHO

    … Using eddy covariance (EC) measurements, exchanges of energy, water, and carbon dioxide between the atmosphere and terrestrial ecosystem have been studied worldwide. …

    Journal of Agricultural Meteorology 76(2), 89-95, 2020

    J-STAGE 

  • Saroma-ko Lagoon Observations for sea ice Physico-chemistry and Ecosystems 2019 (SLOPE2019)  [in Japanese]

    NOMURA Daiki , YABE Itsuka S. , SON Eun Yae , VIVIER Frederic , LOURENCO Antonio , LEBRUN Marion , NOSAKA Yuichi , HIRAWAKE Toru , OOKI Atsushi , AOKI Shigeru , ELSE Brent , WONGPAN Pat , FRIPIAT Francois , INOUE Jun , VANCOPPENOLLE Martin , TOYOTA Takenobu , TANIKAWA Tomonori , KAWAGUCHI Yusuke , ONO Takashi , ISHINO Tomomi , TOZAWA Manami , TAMURA Tetsuya P.

    … In this contribution, we describe a physical, chemical, and ecosystem survey at Saroma-ko Lagoon, conducted over February 23-28, 2019 under the auspices of the SLOPE2019 (Saroma-ko Lagoon Observations for sea ice Physico-chemistry and Ecosystems 2019) program. … flux chamber, and under-ice turbulent heat flux systems were tested for future Arctic and Antarctic expeditions. …

    Bulletin of Glaciological Research 38(0), 1-12, 2020

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  • Canopy fluxes of monoterpene, isoprene and isoprene oxidation products in a pine-oak forest

    MOCHIZUKI Tomoki , TAKANASHI Satoru , WADA Ryuichi , MIYAZAKI Yuzo , NAKANO Takashi , TANI Akira

    … Monoterpenes and isoprene emitted from forest ecosystems contribute to the formation of secondary organic aerosols (SOAs) and photochemical oxidants (O<SUB>x</SUB>) and affect an ecosystem's carbon budget. … The average flux of isoprene during the measurement period was 2.6 times higher than that of monoterpene. …

    Journal of Agricultural Meteorology 76(1), 36-43, 2020

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  • Memory effects of climate and vegetation affecting net ecosystem CO2 fluxes in global forests

    Besnard Simon , Carvalhais Nuno , Arain M. Altaf , Black Andrew , Brede Benjamin , Buchmann Nina , Chen Jiquan , Clevers Jan G. P. W , Dutrieux Loïc P. , Gans Fabian , Herold Martin , Jung Martin , Kosugi Yoshiko , Knohl Alexander , Law Beverly E. , Paul-Limoges Eugénie , Lohila Annalea , Merbold Lutz , Roupsard Olivier , Valentini Riccardo , Wolf Sebastian , Zhang Xudong , Reichstein Markus

    … Current forest CO₂ flux dynamics are controlled by instantaneous climate, soil, and vegetation conditions, which carry legacy effects from disturbances and extreme climate events. … Here, we combined remote sensing, climate, and eddy-covariance flux data to study net ecosystem CO₂ exchange (NEE) at 185 forest sites globally. …

    PLOS ONE 14(2), 2019-02-06

    IR 

  • Diapycnal Mixing Processes and Their Impacts Along the Kuroshio from its Upstream to the Kuroshio Extension  [in Japanese]

    Nagai Takeyoshi

    日本沿岸を流れる黒潮は,流域の気象や海象,生態系に多大な影響を及ぼす.これまでの研究によって,北大西洋のガルフストリームと同様に,表層で貧栄養である黒潮は,その亜表層では栄養塩を下流へ運ぶ栄養塩ストリームであることが明らかとなっている.本稿では,この黒潮の上流から下流である黒潮続流で発生する重要な鉛直混合過程と,その影響について特に黒潮栄養塩ストリームからの栄養塩供給に関して考察を試みた.これまで …

    Bulletin on Coastal Oceanography 57(1), 43-58, 2019

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  • Carbon cycle and methane dynamics of terrestrial ecosystems in the Arctic  [in Japanese]

    Shingubara Ryo , Morozumi Tomoki , Sugimoto Atsuko

    … <p>This review demonstrates carbon cycle and methane dynamics in the Arctic ecosystem, which plays an important role in carbon dioxide and methane emissions because of large stocks of soil organic matter, rapid Arctic warming, and permafrost thaw. … Exchange of carbon dioxide between terrestrial ecosystem and the atmosphere is determined by the balance between ecosystem respiration and primary production. …

    Chikyukagaku 53(4), 183-197, 2019

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  • Export flux of unprocessed atmospheric nitrate from temperate forested catchments: a possible new index for nitrogen saturation

    Nakagawa Fumiko , Tsunogai Urumu , Obata Yusuke , Ando Kenta , Yamashita Naoyuki , Saito Tatsuyoshi , Uchiyama Shigeki , Morohashi Masayuki , Sase Hiroyuki

    … The catchments showed varying flux-weighted average nitrate concentrations of 58.4, 24.4, and 17.1µmol L^−1 in KJ, IJ1, and IJ2, respectively, which correspond to varying export fluxes of nitrate: 76.4, 50.1, and 35.1mmolm^−2 in KJ, IJ1, and IJ2, respectively. … The estimated annual export flux of unprocessed atmospheric nitrate accounted for 9.4 % ± 2.6%, 6.5 % ± 1.8%, and 2.6 % ± 0.6% of the annual deposition flux of atmospheric nitrate in KJ, IJ1, and IJ2, respectively. …

    Biogeosciences 15(22), 7025-7042, 2018-11-22

    IR 

  • Nitrogen fluxes between the ocean and a river basin using stable isotope analysis

    Nakayama Keisuke , Maruya Yasuyuki , Matsumoto Kei , Komai Katsuaki , Kuwae Tomohiro

    … Since marine derived nitrogen (MDN) is hypothesized to largely be transported in particulate form, it is necessary to investigate the contribution of particulate MDN in ground surface soils to the total MDN at the river ecosystem scale. …

    Estuarine Coastal and Shelf Science (212), 286-293, 2018-11-15

    IR 

  • ANNUAL VARIATION OF AIR-SEA CO2 FLUX AT THE RIVER MOUTH AREA AND ITS FACTORS : ANALYSIS OF AN ECOSYSTEM MODEL, EMAGIN_B.C.  [in Japanese]

    相馬 明郎 , 中居 瑞貴 , 久保 篤史 , 桑江 朝比呂

    土木学会論文集. B2, 海岸工学 Journal of Japan Society of Civil Engineers. 土木学会海岸工学委員会 編 74(2), I_1267-1272, 2018

  • Recent changes of climate and livestock productions on the Tibetan Plateau and in situ observations of NEE

    DU Mingyuan , YONEMURA Seiichiro , TANG Yanhong , LI Yingnian , ZHANG Fawei , ZHAO Liang , LI Hongqin , NIU Ben , HE Yongtao , ZHANG Xianzhou , LIU Jingshi

    flux at a wide-distributed alpine meadow since 2001 and at a wide-distributed alpine wetland since 2009 by eddy covariance (EC) method on the Tibetan Plateau. … Recent climatic change and change of livestock production in relation with in situ observation of grassland net ecosystem CO<sub>2</sub> …

    Journal of Arid Land Studies 28(S), 139-142, 2018

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  • Activity Report on Transdisciplinary River Basin Study Group  [in Japanese]

    MARUYA YASUYUKI , KURE SYUICHI , TEBAKARI TAICHI , HOSHIKAWA KEISUKE , AWAYA YOSHIO , MURAOKA HIROYUKI , TAMAGAWA ICHIRO , KOJIMA TOSHIHARU , HARADA MORIHIRO , SAITOH TAKU M , HAYAKAWA HIROSHI , KOMAI KATSUAKI

    人間の多様な活動の場である流域圏では,様々な要因による自然災害(例えば洪水,土砂災害,雪害など)が発生することで,人間とその営みだけでなく,多様な生物を含む生態系や水環境に大きな影響が生じる.このような流域圏における現象を解明し問題を解決するには,例えば水文学,農学,気象学,生態学,社会学など様々な学問分野を統合させた超学際的研究を進める必要がある.これは,「従来の各学問分野で発展してきた体系を縦 …

    Proceeding of Annual Conference 31(0), 50, 2018

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  • Constancy of evapotranspiration at tropical rainforests  [in Japanese]

    Kosugi Yoshiko , Takanashi Satoru , Noguchi Shoji , Itoh Masayuki , Nakaji Tatsuro , Kamakura Mai , Azuma Wakana , Shumsuddin Siti Aisha , Lion Marryanna

    熱帯雨林機能の評価は、世界的にも重要な課題と目されており、数々の数値実験や衛星データを使った広域マッピングなどが世界中でおこなわれているが、水の影響を定量評価するのに、数値モデリングによる解析や、年・月単位降水量・土壌水分等との単なる相関解析だけでは不十分である。現地測定に基づくガス交換の動的変動に関する詳細な情報に基づいて生態系の反応特性を定量化する作業が不可欠であるが、そのような情報はこれまで …

    Proceeding of Annual Conference 31(0), 54, 2018

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  • ANNUAL VARIATION OF AIR-SEA CO2 FLUX AT THE RIVER MOUTH AREA AND ITS FACTORS -ANALYSIS OF AN ECOSYSTEM MODEL, EMAGIN_B.C.-  [in Japanese]

    SOHMA Akio , NAKAI Mizuki , KUBO Atsushi , KUWAE Tomohiro

    沿岸生態系は,炭素を貯留・隔離し,大気中のCO<sub>2</sub>濃度を低下する機能を持つ可能性がある.大気-海洋間のCO<sub>2</sub>フラックスは,沿岸生態系が,大気から炭素を吸収し・貯留し・隔離する,という一連のプロセスを構成する重要な要素である.本研究では,炭酸化学理論,生物生産,移流・拡散過程を包括的に取り扱った生態系モデルを東 …

    Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) 74(2), I_1267-I_1272, 2018

    J-STAGE 

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