A5054150623- Climate change and permafrost
- Plant Water Relations and Carbon Dynamics
- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Tree-ring climate responses
- Climate variability and models
- Geological Studies and Exploration
- Remote Sensing in Agriculture
- Meteorological Phenomena and Simulations
- Hydrology and Watershed Management Studies
- Soil Moisture and Remote Sensing
- Soil and Unsaturated Flow
- Species Distribution and Climate Change
- Forest ecology and management
- Methane Hydrates and Related Phenomena
- Rare-earth and actinide compounds
- Hydrocarbon exploration and reservoir analysis
- Arctic and Antarctic ice dynamics
- Plant responses to elevated CO2
- X-ray Spectroscopy and Fluorescence Analysis
- Wind and Air Flow Studies
- Advanced Chemical Physics Studies
- Plant responses to water stress
- Data-Driven Disease Surveillance
- Peatlands and Wetlands Ecology
Nagoya University
2016-2025
Research Institute for Humanity and Nature
2010-2014
Kobe University
2014
University of Tsukuba
2005-2008
Japan Science and Technology Agency
2006
The University of Tokyo
1995-2003
Tohoku University
1981-1988
Abstract Tundra and boreal ecosystems encompass the northern circumpolar permafrost region are experiencing rapid environmental change with important implications for global carbon (C) budget. We analysed multi-decadal time series containing 302 annual estimates of dioxide (CO 2 ) flux across 70 non-permafrost ecosystems, 672 summer CO 181 ecosystems. find an increase in sink but not despite similar increases uptake. Thus, recent non-growing-season losses have substantially impacted balance...
Abstract This paper presents results of 1 year (from March 25, 2003 to 24, 2004, 366 days) continuous measurements net ecosystem CO 2 exchange (NEE) above a steppe in Mongolia using the eddy covariance technique. The steppe, typical central Mongolia, is dominated by C 3 plants adapted continental climate. following two questions are addressed: (1) how do NEE and its components: gross production (GEP) total respiration ( R eco ) vary seasonally? (2) NEE, GEP, respond biotic abiotic factors?...
Abstract The lack of a standardized database eddy covariance observations has been an obstacle for data‐driven estimation terrestrial CO 2 fluxes in Asia. In this study, we developed such using 54 sites from various databases by applying consistent postprocessing gross primary productivity (GPP) and net ecosystem exchange (NEE). Data‐driven was conducted machine learning algorithm: support vector regression (SVR), with remote sensing data 2000 to 2015 period. Site‐level evaluation the...
Abstract The memory timescale that characterizes root‐zone soil moisture remains the dominant measure in seasonal forecasts of land‐climate interactions. This is a quasi‐deterministic associated with losses (e.g., evapotranspiration) from column and often interpreted as persistence states. Persistence, however, represents distribution time periods where resides above or below some prescribed threshold therefore inherently probabilistic. Using multiple data sets collected at high resolution...
Abstract. Past efforts to synthesize and quantify the magnitude change in carbon dioxide (CO2) fluxes terrestrial ecosystems across rapidly warming Arctic–boreal zone (ABZ) have provided valuable information but were limited their geographical temporal coverage. Furthermore, these been based on data aggregated over varying time periods, often with only minimal site ancillary data, thus limiting potential be used large-scale budget assessments. To bridge gaps, we developed a standardized...
ABSTRACT Continuous observation over the last decade has revealed evidence of abrupt land surface moistening as well rapid soil warming within active layer and upper part permafrost central Lena River basin in eastern Siberia. The present study examined relationship between degradation ecohydrological change this region. Increases depth recorded since winter 2004 resulting from increases moisture saturation have resulted thawing causing thermokarst subsidence, which negatively impacted...
The examination of vegetation productivity and use light water resources is important for understanding the carbon cycles in semiarid arid environments. We made continuous measurements dioxide vapor fluxes over an steppe ecosystem Mongolia by using eddy covariance (EC) technique. These allow EC‐estimated gross (GEP), efficiency (LUE), (WUE) steppe. Daily variations GEP, LUE, WUE were associated with daily incident photosynthetically active radiation (PAR), ambient temperature ( T a ),...
Abstract Recent studies suggest that forest vulnerability to tree mortality has increased as a result of extreme climate events such severe drought and heavy rain. However, little is known about the processes, particularly when they are induced by A dendroecological analysis was conducted on living dead trees in Siberian larch using chronologies 30 years radial growth carbon isotope (Δ 13 C) discrimination. The demonstrates relationship between rain mortality. Radial Δ C patterns at wet...
Abstract. Eddy covariance observations play a pivotal role in understanding the land–atmosphere exchange of energy, water, carbon dioxide (CO2), and other trace gases, as well global cycle earth system. To promote networking individual measurements sharing data, FLUXNET links regional networks researchers studying processes. JapanFlux was established 2006 country branch AsiaFlux. Despite growing number shared data globally, availability Asia is currently limited. In this study, we developed...
Mongolian boreal forest merits special attention since it is located in the transitional area between southern Siberian and Asian steppe zone, a vulnerable region being potentially affected by global warming anthropogenic activities. This paper presents first full‐year‐long continuous measurements of net ecosystem CO 2 flux (NEE) made over montane larch ( Larix sibirica Ledeb.) Mongolia from 25 March 2003 to 24 2004 (366 days) using eddy covariance technique. The hourly maximum uptake was...
ABSTRACT This study investigated evapotranspiration and CO 2 exchange, observed by the eddy covariance method, over two larch‐dominated forests, in middle part of Lena basin, eastern Siberia. Compared with Spasskaya Pad (SP) forest, Elgeeii (EG) forest had more plant biomass a soil texture that allowed for larger water retention. Observations three growing seasons revealed sites similar seasonal patterns meteorological conditions almost same total evapotranspiration; however, net gross...
Abstract The fate of a boreal forest may depend on the trend in its normalized difference vegetation index (NDVI), such as whether NDVI has been increasing significantly over past few decades. In this study, we analyzed responses two Siberian larch forests at Spasskaya Pad and Elgeeii eastern Siberia to various waterlogging-induced disturbances, using satellite-based meteorological data for 2000–2019 period. experienced waterlogging (i.e. flooding events caused by abnormal precipitation)...
Evapotranspiration (ET) is not only a vital component of water budget, but also plays an important role in the energy budget earth-atmospheric system, ultimately driving many regional and global scale climatological processes. This paper describes ET characteristics factors controlling across 17 forest sites East Asia (2°S to 64°N latitude). was measured using eddy covariance technique at each site. Daytime dry-canopy data for growing season were used this study. Growing mean gradually...
We summarized our recently-published papers on greenhouse gas exchanges at two important boreal regions underlain by permafrost: eastern Siberia and interior Alaska. Relevant literatures were also referred to, future research directions the high-latitude terrestrial processes suggested. Long-term monitoring of CO2 fluxes forests revealed that anomalous weather disturbances changed balance. More than a decade is required to return sink burned in Anomalous high precipitation altered forest...
Abstract Temporal variability in root zone soil moisture content ( w ) exhibits a Lorentzian spectrum with memory dictated by damping term when forced white‐noise precipitation. In the context of regional dimming, radiation and precipitation are needed to reproduce trends prompting interest how is altered radiative forcing. A hierarchy models that sequentially introduce precipitation, net radiation, effect on evaporative drainage losses was used analyze at subtropical temperate forested...