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Tomoya IWATA


Kushiro River

Food web dynamics in drainage networks

Drainage basin is a landscape unit delineated by watershed divides that form a spatially discrete hydrological system. Within the system, streams not only route the material flow downstream but function as energy artery that transports organic matter and nutrients to the various spatial elements. My group investigates the routes and dynamics of such material flow that influences food web dynamics in streams, lakes, forests and even urban ecosystems in drainage networks.

Lab    Classes   

Dept. of Ecosocial System Eng. | University of Yamanashi |



Tomoya IWATA (Mr.)
Occupation: Assistant Professor (Dr Sci.)
Department of Ecosocial System Engineering, University of Yamanashi
Research field: Watershed Ecology
Contact address: 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan

Email: tiwata@yamanashi.ac.jp

Education and Academic Career

 Received Bachelor of Fishery from the Faculty of Fisheries, Hokkaido University in March 1998.
 Received Master of Agriculture from the Graduate School of Agriculture, Hokkaido University in March 2000.
 Received Doctor of Science from the Graduate School of Science, Kyoto University in March 2003.
 Assistant Professor, 2003-, University of Yamanashi

Current research
1) Basin respiration and the fate of terrestrial organic carbon in the Fuji River watershed

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2) Terrestrial subsidies to aquatic food webs in alpine and subalpine lakes

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3) Carbon metabolism of aquatic food webs in alpine and subalpine lakes

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4) Landscape genetics: the genetic structure of amphibians in highly fragmented landscapes

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5) Carbon dioxide and methane emissions from a hydroelectric reservoir

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Peer-reviewed publications

Sikiu River

  • Santona Khatun, Tomoya Iwata*, Hisaya Kojima, Manabu Fukui, Takuya Aoki, Seito Mochizuki, Azusa Naito, Ai Kobayashi, Ryo Uzawa (2019)
    Aerobic methane production by planktonic microbes in lakes
    Science of the Total Environment in press

  • Takuya Ishida*, and others (2019)
    Identification of phosphorus sources in a watershed using a phosphate oxygen isoscape approach
    Environmental Science and Techonology 53: 4707-4716. Abstract

  • Anandeeta Gurung*, Tomoya Iwata, Daisuke Nakano, and Jotaro Urabe (2019)
    River metabolism along a latitudinal gradient across Japan and in a global scale
    Scientific Reports 9: 4932. Abstract

  • Sahadevan Seena*, and others (2019)
    Biodiversity of leaf litter fungi in streams along a latitudinal gradient
    Science of the Total Environment 661: 306-315. Abstract

  • Scott D. Tiegs*, David M. Costello, and others (2019)
    Global patterns and drivers of ecosystem functioning in rivers and riparian zones
    Science Advances 5: eaav0486 Abstract

  • Chia-Ying Ko*, Tomoya Iwata, Jun-Yi Lee, Aya Murakami, Junichi Okano, Naoto F. Ishikawa, Yoichiro Sakai, Ichiro Tayasu, Masayuki Itoh, Uhram Song, Hiroyuki Togashi, Shinich Nakano, Nobuhito Ohte and Noboru Okuda (2019)
    Assessing alpha and beta diversities of benthic macroinvertebrates and their environmental drivers between watersheds with different levels of habitat transformation in Japan
    Marine and Freshwater Research in press Abstract

  • Mitsuko Yumoto*, Tomoya Iwata and Tetsu Hirata (2018)
    Species distribution and predictive habitat modelling of amphibians in Yamanashi Prefecture, Japan
    Bulletin of the Herpetological Society of Japan 2018: 1-13. Abstract

  • Ryuichiro Shinohara*, Tomoya Iwata, Yoshiki Ikarashi and Tomoharu Sano (2018)
    Detection of 2-aminoethylphosphonic acid in suspended particles in an ultraoligotrophic lake: a two-dimensional nuclear magnetic resonance (2D-NMR) study
    Environmental Science and Pollution Research 25: 30739-30743. Abstract

  • Melody Cabrera Ospino, Hisaya Kojima*, Tomohiro Watanabe, Tomoya Iwata and Manabu Fukui (2018)
    Diversity of anaerobic arsenite‐oxidizing bacteria in low‐salt environments analyzed with a newly developed PCR‐based method
    Limnology 19: 177-183. Abstract

  • Yuta Kobayashi and Tomoya Iwata* (2017)
    Nitrogen and phosphorus dynamics in a large river estimated by an in situ Lagrangian tracking approach
    Freshwater Biology 62: 1997-2007. Abstract

  • Luz Boyero*, Manuel A.S. Graca, and other 30 authors (2017)
    Riparian plant litter quality increases with latitude
    Scientific Reports 7: 10562. Abstract

  • Naoto Ishikawa*, Yoshito Chikaraishi, Naohiko Ohkouchi, Aya Murakami, Ichiro Tayasu, Hiroyuki Togashi, Jun-ichi Okano, Yoichiro Sakai, Tomoya Iwata, Michio Kondoh, and Noboru Okuda (2017)
    Integrated trophic position decreases in more diverse communities of stream food webs
    Scientific Reports 7: 2130. Abstract

  • Tomohiro Watanabe*, Aya Miura, Tomoya Iwata, Hisaya Kojima, and Manabu Fukui (2017)
    Dominance of Sulfuritalea species in nitrate-depleted water of a stratified freshwater lake and arsenate respiration ability within the genus
    Environmental Microbiology Reports doi: 10.1111/1758-2229.12557. Abstract

  • Luz Boyero*, Richard G. Pearson, and other 32 authors (2016)
    Biotic and abiotic variables influencing plant litter breakdown in streams: a global study
    Proceedings of the Royal Society B: Biological Sciences 283: 20152664. Abstract

  • Yuta Fujiwara*, Tomoya Iwata, Jotaro Urabe and Satoshi Takeda (2016)
    Life history traits and ecological conditions influencing the symbiotic relationship between the flatworm Stylochoplana pusilla and host snail Monodonta labio
    Journal of the Marine Biological Association of the United Kingdom 96: 667-672. Abstract

  • Tomoya Iwata*, Hayato Aoyama (2015)
    Dynamics of phosphorus transport and retention in a river network
    Chikyu Kankyo 20: 27-34. Abstract

  • Hisaya Kojima*, Tomohiro Watanabe, Tomoya Iwata and Manabu Fukui (2014)
    Identification of major planktonic sulfur oxidizers in stratified freshwater lake
    PLOS ONE (In press)

  • Tomoya Iwata*, Takao Suzuki, Hiroyuki Togashi, Naoto Koiwa, Hideaki Shibata and Jotaro Urabe (2013)
    Fluvial transport of carbon along the river-to-ocean continuum and its potential impacts on a brackish water food web in the Iwaki River watershed, northern Japan
    Ecological Research 28: 703-716. Abstract

  • Jun-ichi Tsuboi*, Tomoya Iwata, Kentaro Morita, Shinsuke Endou, Hideki Oohama and Kouichi Kaji (2013)
    Strategies for the conservation and management of isolated salmonid populations: lessons from Japanese streams
    Freshwater Biology 58: 908-917. Abstract

  • Hisaya Kojima*, Masazumi Tsutsumi, Kanako Ishikawa, Tomoya Iwata, Marc Mussmann and Manabu Fukui (2012)
    Distribution of putative denitrifying methane oxidizing bacteria in sediment of a freshwater lake, Lake Biwa
    Systematic and Applied Microbiology 35: 233-238. Abstract

  • Masanori Fujii, Hisaya Kojima*, Tomoya Iwata, Jotaro Urabe and Manabu Fukui (2012)
    Dissolved organic carbon as major environmental factor affecting bacterioplankton communities in mountain lakes of eastern Japan
    Microbial Ecology 63: 496-508. Abstract

  • Luz Boyero*, Richard G. Pearson, and other 33 authors (2011)
    A global experiment suggests climate warming will not accelerate litter decomposition in streams but may reduce carbon sequestration
    Ecology Letters 14: 289-294. Abstract

  • Masazumi Tsutsumi, Tomoya Iwata, Hisaya Kojima* and Manabu Fukui (2011)
    Spatio-temporal variations in an assemblage of closely related planktonic aerobic methanotrophs
    Freshwater Biology 56: 342-351. Abstract

  • Jotaro Urabe*, Tomoya Iwata, Yosuke Yagami, Eriko Kato, Takao Suzuki, Shuji Hino and Syuhei Ban (2011)
    Within-lake and watershed determinants of carbon dioxide in the surface water: a comparative analysis for a variety of lakes in Japanese Islands
    Limnology and Oceanography 56: 49-60. Abstract

  • Tomoya Iwata*, Jotaro Urabe and Hiromune Mitsuhashi (2010)
    Effects of drainage-basin geomorphology on insectivorous bird abundance in temperate forests
    Conservation Biology 24: 1278-1289. Abstract

  • David A. Spiller*, Jonah Piovia-Scott, Amber N. Wright, Louie H. Yang, Gaku Takimoto, Thomas W. Schoener and Tomoya Iwata (2010)
    Marine subsidies have multiple effects on coastal food webs
    Ecology 91: 1424-1434. Abstract

  • Ayato Kohzu*, Tomoya Iwata, Makoto Kato, Junko Nishikawa, Eitaro Wada, N. Amartuvshin, B. Namkhaidorj and Noboru Fujita (2009)
    Food webs in Mongolian grasslands: The analysis of 13C and 15N natural abundances
    Isotopes in Environmental and Health Studies 45: 208-219. Abstract

  • Nguyen T. Hai Yen*, Kengo Sunada, Satoru Oishi, Kou Ikejima and Tomoya Iwata (2009)
    Stock assessment and fishery management of Henicorhynchus spp., Cyclocheilichthys enoplos and Channa micropeltes in the Tonle Sap Great Lake, Cambodia
    Journal of Great Lakes Research 35: 169-174. Abstract

  • Hisaya Kojima*, Tomoya Iwata and Manabu Fukui (2009)
    DNA-based analysis of planktonic methanotrophs in a stratified lake
    Freshwater Biology 54: 1501-1509. Abstract

  • Gaku Takimoto*, Tomoya Iwata and Masashi Murakami (2009)
    Timescale hierarchy determines the indirect effects of fluctuating subsidy inputs on in situ resources
    The American Naturalist 173: 200-211. Abstract

  • Junko Nishikawa, Ayato Kohzu, Narin Boontanon, Tomoya Iwata, Takuya Tanaka, Nanako O. Ogawa, Reiichiro Ishii and Eitaro Wada* (2009)
    Isotopic composition of nitrogenous compounds with emphasis on anthropogenic loading in river ecosystems
    Isotopes in Environmental and Health Studies 45: 27-40. Abstract

  • Nguyen T. Hai Yen*, Kengo Sunada, Satoru Oishi, Yasusi Sakamoto, Kou Ikejima and Tomoya Iwata (2008)
    The spatial distribution of fish species catches in relation to catchment and habitat features in the floodplain lot fisheries of Tonle Sap Lake, Cambodia
    Journal of Fisheries and Aquatic Science 3: 213-227. Abstract

  • Tomoya Iwata*, Tetsuya Takahashi, and other 24 authors (2007)
    Metabolic balance of streams draining urban and agricultural watersheds in central Japan
    Limnology 8: 243-250. Abstract

  • Tomoya Iwata* (2006)
    Linking stream habitats and spider distribution: spatial variations in trophic transfer across a forest-stream boundary
    Ecological Research 22: 619-628. Abstract

  • Shinsuke Endou*, Jun-ichi Tsuboi and Tomoya Iwata (2006)
    Effects of damming on the persistence of white-spotted charr and red-spotted masu salmon populations
    Japanese Journal of Conservation Ecology 11: 4-12 (in Japanese) Abstract

  • Chika Kato, Tomoya Iwata* and Eitaro Wada (2004)
    Prey use by web-building spiders: stable isotope analyses of trophic flow at a forest-stream ecotone
    Ecological Research 19: 633-643. Abstract

  • Ayato Kohzu*, Chika Kato, Tomoya Iwata, Daisuke Kishi, Masashi Murakami, Shigeru Nakano and Eitaro Wada (2004)
    Stream food web fueled by methane-derived carbon
    Aquatic Microbial Ecology 36: 189-194. Abstract

  • Mikio Inoue*, Tomoya Iwata, Shigeru Nakano, Atsushi Doi and Hitoshi Miyasaka (2003)
    Fish assemblage composition, abundance-habitat relationships and habitat use in tropical rain forest streams, Sarawak, Borneo: effects of past deforestation
    Biosphere Conservation 5: 71-86.

  • Chika Kato, Tomoya Iwata*, Shigeru Nakano and Daisuke Kishi (2003)
    Dynamics of aquatic insect flux affects distribution of riparian web-building spiders
    Oikos 103: 113-120. Abstract PDF

  • Tomoya Iwata*, Shigeru Nakano and Masashi Murakami (2003)
    Stream meanders increase insectivorous bird abundance in riparian deciduous forests
    Ecography 26: 325-337. Abstract  PDF

  • Tomoya Iwata*, Mikio Inoue, Shigeru Nakano, Hitoshi Miyasaka, Atsushi Doi and Alan P. Covich (2003)
    Shrimp abundance and habitat relationships in tropical rain-forest streams, Sarawak, Borneo
    Journal of Tropical Ecology 19: 387-395. Abstract

  • Tomoya Iwata*, Shigeru Nakano and Mikio Inoue (2003)
    Impacts of past riparian deforestation on stream communities in a tropical rain forest in Borneo
    Ecological Applications 13: 461-473. Abstract

  • Tomoya Iwata*, Susumu Shimizu, Yasuzumi Fujimori and Teisuke Miura (2003)
    Incidental catch of harbor porpoises in set-nets in the coastal waters of southern Hokkaido, Japan
    Fisheries Science 69: 657-659. Abstract

  • Gaku Takimoto*, Tomoya Iwata and Masashi Murkami (2002)
    Seasonal subsidy stabilizes food web dynamics: balance in a heterogeneous landscape
    Ecological Research 17: 433-439. Abstract

  • Motoharu Konishi, Shigeru Nakano and Tomoya Iwata* (2001)
    Trophic cascading effects of predatory fish on leaf litter processing in a Japanese stream
    Ecological Research 16: 415-422. Abstract

  • Atsushi Doi*, Tomoya Iwata, Mikio Inoue, Hitoshi Miyasaka, Mohamad Shahbudin Sabki and Shigeru Nakano (2001)
    A collection of freshwater fishes from the Rayu basin of western Sarawak, Malaysia
    Raffles Bulletin of Zoology 49: 13-17. Abstract



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  • Ecological Research Award, 2005

  • Ecological Research Award, 2002



Editorial works