Tomomichi Kato

Abstract Three years of eddy covariance measurements were used to characterize the seasonal and interannual variability of the CO 2 fluxes above an alpine meadow (3250 m a.s.l.) on the Qinghai‐Tibetan Plateau, China. This alpine meadow was a weak sink for atmospheric CO 2 , with a net ecosystem production (NEP) of 78.5, 91.7, and 192.5 g C m −2 yr −1 in 2002, 2003, and 2004, respectively. The prominent, high NEP in 2004 resulted from the combination of high gross primary production (GPP) and low

Abstract Asian terrestrial ecosystems cover an extensive area characterized by a large variety in climates and ecosystem properties. The observations of ecosystem CO 2 flux in this area are increasing both in duration and spatial density, but no synthesis has yet been conducted. We surveyed CO 2 flux observation data obtained by eddy covariance methods at 49 sites in terrestrial Asia. The measurements at most sites (44 of 49) began after 2000. The net ecosystem uptake of CO 2 (NEE) varied greatl

We measured the net ecosystem CO 2 exchange (NEE) in an alpine meadow ecosystem (latitude 37°29′–45′N, longitude 101°12′–23′E, 3250 m above sea level) on the Qinghai‐Tibetan Plateau throughout 2002 by the eddy covariance method to examine the carbon dynamics and budget on this unique plateau. Diurnal changes in gross primary production (GPP) and ecosystem respiration (R e ) showed that an afternoon increase of NEE was highly associated with an increase of R e . Seasonal changes in GPP correspond

Abstract. Terrestrial productivity in semi-arid woodlands is strongly susceptible to changes in precipitation, and semi-arid woodlands constitute an important element of the global water and carbon cycles. Here, we use the Carbon Cycle Data Assimilation System (CCDAS) to investigate the key parameters controlling ecological and hydrological activities for a semi-arid savanna woodland site in Maun, Botswana. Twenty-four eco-hydrological process parameters of a terrestrial ecosystem model are opti

Forest biomass is a crucial component of the global carbon budget in climate change studies. Therefore, it is essential to develop a credible way to estimate forest biomass as carbon stock. Our study used PALSAR-2 (ALOS-2) and Sentinel-2 images to drive the Random Forest regression model, which we trained with airborne lidar data. We used the model to estimate forest aboveground biomass (AGB) of two significant coniferous trees, Japanese cedar and Japanese cypress, in Ibaraki Prefecture, Japan.

Abstract The FAO basal crop coefficient K cb and the soil evaporation coefficient K e for a sparse sorghum field in one growing season were estimated using the compartment model (Shuttleworth–Wallace model; S–W model), which separately estimates transpiration from crops and evaporation from the soil. The K cb had a low value of 0.10 ( K cb , ini ) during the initial period, increased rapidly to a maximum of 0.98 ( K cb , mid ) at midseason, and decreased rapidly to 0.53 ( K cb, end ) by the end

The combined measurements of N2O concentration, flux, and isotopomeric signatures provide a robust estimation of N2O circulation dynamics in alpine ecosystems on the QTP, which would contribute to the development of ecosystem nitrogen cycle model.