Faculty Profiles - KOTANI, Ayumi

Papers - KOTANI, Ayumi

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The GRENE-TEA model intercomparison project (GTMIP) Stage 1 forcing data set

Sueyoshi T.

Earth System Science Data Vol. 8 ( 1 ) page： 1 - 14 2016.1

The effect of assimilating satellite-derived soil moisture data in SiBCASA on simulated carbon fluxes in Boreal Eurasia

van der Molen M. K., de Jeu R. A. M., Wagner W., van der Velde I. R., Kolari P., Kurbatova J., Varlagin A., Maximov T. C., Kononov A. V., Ohta T., Kotani A., Krol M. C., Peters W.

HYDROLOGY AND EARTH SYSTEM SCIENCES Vol. 20 ( 2 ) page： 605 - 624 2016

The GRENE-TEA model intercomparison project (GTMIP) Stage 1 forcing data set

Sueyoshi T., Saito K., Miyazaki S., Mori J., Ise T., Arakida H., Suzuki R., Sato A., Iijima Y., Yabuki H., Ikawa H., Ohta T., Kotani A., Hajima T., Sato H., Yamazaki T., Sugimoto A.

EARTH SYSTEM SCIENCE DATA Vol. 8 ( 1 ) page： 1-14 2016

The effect of assimilating satellite derived soil moisture in SiBCASA on simulated carbon fluxes in Boreal Eurasia

Van Der Molen M.

Hydrology and Earth System Sciences Discussions Vol. 12 ( 9 ) page： 9003 - 9054 2015.9

Biogeochemical nitrogen properties of forest soils in the Japanese archipelago

Urakawa Rieko, Ohte Nobuhito, Shibata Hideaki, Tateno Ryunosuke, Hishi Takuo, Fukushima Keitaro, Inagaki Yoshiyuki, Hirai Keizo, Oda Tomoki, Oyanagi Nobuhiro, Nakata Makoto, Toda Hiroto, Kenta Tanaka, Fukuzawa Karibu, Watanabe Tsunehiro, Tokuchi Naoko, Nakaji Tatsuro, Saigusa Nobuko, Yamao Yukio, Nakanishi Asami, Enoki Tsutomu, Ugawa Shin, Hayakawa Atsushi, Kotani Ayumi, Kuroiwa Megumi, Isobe Kazuo

ECOLOGICAL RESEARCH Vol. 30 ( 1 ) page： 1-2 2015.1

The GRENE-TEA model intercomparison project (GTMIP): overview and experiment protocol for Stage 1

Miyazaki S., Saito K., Mori J., Yamazaki T., Ise T., Arakida H., Hajima T., Iijima Y., Machiya H., Sueyoshi T., Yabuki H., Burke E. J., Hosaka M., Ichii K., Ikawa H., Ito A., Kotani A., Matsuura Y., Niwano M., Nitta T., O'ishi R., Ohta T., Park H., Sasai T., Sato A., Sato H., Sugimoto A., Suzuki R., Tanaka K., Yamaguchi S., Yoshimura K.

Geoscientific Model Development Vol. 8 ( 9 ) page： 2841 - 2856 2015

Radiative and precipitation controls on root zone soil moisture spectra

Nakai Taro, Katul Gabriel G, Kotani Ayumi, Igarashi Yasunori, Ohta Takeshi, Suzuki Masakazu, Kumagai Tomo'omi

GEOPHYSICAL RESEARCH LETTERS Vol. 41 ( 21 ) page： 7546 - 7554 2014.11

Radiative and precipitation controls on root zone soil moisture spectra Reviewed

Nakai, T., Katul, G.G., Kotani, A., Igarashi, Y., Ohta, T., Suzuki, M., Kumagai, T.

Geophysical Research Letters Vol. 41 page： 7546-7554 2014.11

Effects of waterlogging on water and carbon dioxide fluxes and environmental variables in a Siberian larch forest, 1998-2011

Ohta Takeshi, Kotani Ayumi, Iijima Yoshihiro, Maximov Trofim C., Ito Syogo, Hanamura Miho, Kononov Alexander V., Maximov Ayal P.

AGRICULTURAL AND FOREST METEOROLOGY Vol. 188 page： 64 - 75 2014.5

Sap flow changes in relation to permafrost degradation under increasing precipitation in an eastern Siberian larch forest. Ecohydrology

Iijima, Y, Ohta, T, Kotani, A, Fedorov, A, Kodama, Y, Maximov, T

Ecohydrology Vol. 7 ( 2 ) page： 177 - 187 2014.4

Temporal variations in the linkage between the net ecosystem exchange of water vapour and CO2 over boreal forests in eastern Siberia

Kotani, A, Kononov, A, Ohta, T, Maximov, T

Ecohydrology Vol. 7 ( 2 ) page： 209 - 225 2014.4

Language：English Publishing type：Research paper (scientific journal)

This study investigated evapotranspiration and CO2 exchange, observed by the eddy covariance method, over two larch-dominated forests, in the middle part of the Lena basin, eastern Siberia. Compared with the Spasskaya Pad (SP) forest, the Elgeeii (EG) forest had more plant biomass and a soil texture that allowed for larger water retention. Observations in three growing seasons revealed that the two sites had similar seasonal patterns of meteorological conditions and almost the same total evapotranspiration; however, the net and gross uptakes of CO2 at the EG forest were 1·61 and 1·31 times those at the SP forest, respectively. The difference in aboveground biomass was probably responsible for the higher productivity at EG. Less aboveground biomass would result in less transpiration by trees at SP, which would be compensated for in total evapotranspiration by soil evaporation and transpiration by the forest floor vegetation. It is likely that forest transpiration is commonly optimized to the same level of evapotranspiration under similar meteorological conditions through differences in the contributions of evapotranspiration from the forest floor vegetation and the soil water availability. Water use efficiency (WUE) displayed different patterns, reflecting the seasonal variations in each flux. Seasonal sequences in the WUE at EG indicated a midsummer depletion, which is commonly observed in forest ecosystems under a broad climate. Daily variation corresponding to the vapour pressure deficit and the cloud cover conditions (reduced solar radiation) was also observed. In contrast, WUE was relatively invariable at the seasonal and daily scales at SP.

DOI： 10.1002/eco.1449

Web of Science

Scopus

International Joint Conference of 11th AsiaFlux International Workshop, 3rd HESSS and 14th Annual Meeting of KSAFM “Communicating Science to Society: Coping with Climate Extremes for Resilient Ecological-Societal Systems”の報告

丸山篤志, 宮崎真, 小谷亜由美, 栗林正俊, 斎藤琢, 小野圭介

生物と気象 Vol. 14 page： D1-7 2014.1

Effects of waterlogging on water and carbon dioxide fluxes and environmental variables in a Siberian larch forest Reviewed

Ohta, T., Kotani, A., Iijima, Y., Maximov, T., Ito, S., Hanamura, M., Kononov, A., Maximov, A.

Agricultural and Forest Meteorology Vol. 188 page： 64-75 2014.1

Water, Energy and Carbon Cycle in the Larch Wood of East Siberia

OHTA Takeshi, KOTANI Ayumi

Water Science Vol. 58 ( 5 ) page： 43 - 73 2014

Primary factors in interannual variation of latent heat fluxes from overstory and understory in Siberian larch forest

Saito Atsushi, Kotani Ayumi, Ohta Takeshi, Iijima Yoshihiro

The Japanese Forest Society Congress Vol. 125 ( 0 ) page： 146 - 146 2014

Changes in eco-hydrological systems under recent climate change in eastern Siberia Reviewed

Hiyama TETSUYA, Ohta TAKESHI, Sugimoto ATSUKO, Yamazaki TAKESHI, Oshima KAZUHIRO, Yonenobu HITOSHI, Yamamoto KAZUKIYO, Kotani AYUMI, Park HOTAEK, Kodama Yuji, ther

IAHS Publication Vol. 360 page： 155 - 160 2013.1

Language：English Publishing type：Research paper (scientific journal)

Global warming is likely to transform Siberian environments. Recent eco-hydrological evidence indicates that water and carbon cycles have been changing rapidly, with potentially serious effects on the Siberian flora and fauna. We have comprehensively analysed dendrochronological, hydrological, and meteorological data and satellite remote sensing data to track changes in vegetation and the water and carbon cycles in the Lena River Basin, eastern Siberia. The basin is largely covered with larch forest and receives little precipitation. However, from 2005 to 2008 the central part of the basin experienced an extraordinarily high level of precipitation in late summer and winter. This resulted in the degradation of permafrost, forest, and hydrological elements in the region. Dendrochronological data implied that this event was the only incidence of such conditions in the previous 150 years. Based on data collected before and after the event, we developed a permafrost-ecosystem model, including surface soil freeze-thawing processes, to better represent the heat, water, and carbon fluxes in the region. We focused on the surface soil layer, in which an increased thawing depth is now apparent, surface soil moisture, and net primary production. An analysis of observed and model-simulated data indicated that the annual maximum thawing depth (AMTD) had increased gradually on a decadal scale and deepened abruptly after 2005. Climatological analyses of atmospheric water circulation over the region indicated that the recent increases in precipitation over the central Lena River Basin were partly related to cyclone activity. Consequently, the increased precipitation from late-summer to winter resulted in increases in soil moisture, soil temperature, and AMTD in the region. © 2013 IAHS Press.

Scopus

Other Link： http://orcid.org/0000-0002-1596-7543

Changes in eco-hydrological systems under recent climate change in eastern Siberia

Hiyama Tetsuya, Ohta Takeshi, Sugimoto Atsuko, Yamazaki Takeshi, Oshima Kazuhiro, Yonenobu Hitoshi, Yamamoto Kazukiyo, Kotani Ayumi, Park Hotaek, Kodama Yuji, Hatta Shigemi, Fedorov Alexander N., Maximov Trofim C.

COLD AND MOUNTAIN REGION HYDROLOGICAL SYSTEMS UNDER CLIMATE CHANGE: TOWARDS IMPROVED PROJECTIONS Vol. 360 page： 155 - 160 2013

Changes in eco-hydrological systems under recent climate change in eastern Siberia

Hiyama T.

IAHS-AISH Proceedings and Reports Vol. 360 page： 155 - 160 2013

Interannual variation of evapotranspiration in an eastern Siberian larch forest

Xue Bao-Lin, Komatsu Hikaru, Kumagai Tomo'omi, Kotani Ayumi, Otsuki Kyoichi, Ohta Takeshi

HYDROLOGICAL PROCESSES Vol. 26 ( 15 ) page： 2360 - 2368 2012.7

Seasonal variability of scalar turbulent transport above forest canopy

Kotani Ayumi, Hamazaki Shunki, Ohta Takeshi

Proceeding of Annual Conference Vol. 25 ( 0 ) page： 276 - 276 2012

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：THE JAPAN SOCIETY OF HYDROLOGY AND WATER RESOURCES

This study investigates seasonal variation in applicability of the turbulent similarity theory, and similarity or dissimilarity in the scalar transfer characteristics observed over forest canopy in the tropical monsoon, temperate, and boreal region. Deviation from the similarity theory and the small transfer efficiency was observed for CO<sub>2</sub> variation at the boreal and temperature variation at the cool-temperate forest. Forests including deciduous trees showed clear seasonal variation in not only scalar flux itself but also its transfer characteristics especially in the case of CO<sub>2</sub> variation, while the evergreen forest did not present such seasonal variation.

DOI： 10.11520/jshwr.25.0.276.0

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