Updated: 2012-09-05

Yamashiro forest hydrology research site (YMS)

Two observation towers (left: ridge tower, right: valley tower) in broadleaf forest in Yamashiro

Overview of this site

Yamashiro forest hydrology research site is located in the southern part of Kyoto prefecture. The site is in a broadleaf forest which is built up on weathered granite and the forest is also one of headstreams of Kizu River. The region used to be cleared off as it was managed as a suburban forest, until a century ago, when the green development operated by Johannis de Rijke has brought vegetation restoration. After the invasion by pine wilt disease in 1980’s, Konara oak has taken over and the forest is now regenerated. Such secondary forests are widely distributed throughout Kyoto-Osaka-Kobe and Seto Inland Sea coast area. Yamashiro research site was established to study internal mechanism of carbon circulation and to develop the flux observation method in such ecosystem. This site can be characterized by twin towers (one on the ridge and the other in the valley) to observe space variation in complex terrain. Several cooperative projects are carried out with neighboring universities to quantify the amount of fixed carbon and to find out the mechanism of carbon cycle. Our research activity covers wide range of areas which include long term continuous observation of seasonal change using automated chambers and REA observation of trace gas flux as well as common ecological investigations. Some studies are focusing particularly on high respiration activity of root and litter, and some are concentrating on the loss of noctornal flux by drainage flow or horizontal advection.

Position34 deg 47.687 min N (34.7948 deg N),
135 deg 50.770 min E (135.8462 deg E)
Climate ClassificationTemperate (Cfa, Temperate - Fully humid - Hot summer)
Annual Mean Temperature14.7°C(year 2000-2002)
Annual Mean Precipitation1095mm(year 2000-2002)
Annual Mean Solar Raadiation11.9MJm-2day-1(year 2000-2002)
Monthly mean temperature and precipitation
(year 2000-2002)
Monthly mean solar radiation (year 2000-2002)
VegetationWarm temperate broadleaf forest
AreaForest community: > 10km2
Ecosystem research area: 1.7ha,
Hydrological catchment area: 1.6ha
Fetch> 2km
Dominant SpeciesQuercus serrata (Konara oak), Ilex pedunculosa (japanese holly), Lyonia elliptica (tree Lyonia), Alnus Sieboldiana (alder), Clethra barbinervis (japanese sweetspire), Eurya japonica (japanese eurya), Pinus densiflora (japanese red pine), Robinia Pseudo-acacia (locust tree)
Canopy Height6m-20m, approx. 12m in average
Breast High Diameter7.4cm in average, 50.2cm in Max. (Hinoki cypress)
AgeIdentified to be oldest red pine: 119years (BHD 34.8cm, investigated in 2000)
Leaf Area Index4.42 in summer and 2.70 in winter (LAI-2000)
Community StructureOverstory, middlestory, understory
Soil TypeImmature soil, lm
Artificial DisturbanceMore than 2km apart from major roads and inhabitable area
Observation Period
Period1 November 1999 to present
Tower HeightRidge tower: 26.5m
Valley tower: 35m
Access to Tower TopPossible
Electric Power SupplyCommercial power supply AC100V 60A
Communication EquipmentNot available (Accessible by mobile phone)
AccommodationNot available (2km to a public camp site)


 Name and ModelLevel
 Upper: ridge tower
 Lower: valley tower
Downward Short-wave RadiationEKO MR-22
Kipp&Zonen, CM-7B
26.2 m
36.1 m
Upward Short-wave RadiationEKO MR-22
Kipp&Zonen, CM-7B
26.2 m
36.1 m
Downward Long-wave RadiationEppley, PIR26.2 m
Upward Long-wave RadiationEppley, PIR26.0 m
Net RadiationEKO, CN-1126.2 m
36.1 m
Downward PPFDLI-COR, LI190-SA26.2 m
Upward PPFDEKO ML-020-26.2 m
Downward PPFD below CanopyN/A-
Downward Short-wave Radiation below CanopyEKO, MS-420.5 m
All-wave Net RadiationN/A-
Air temperaturePlatinum resistance thermometer
Vaisala HMP-45D
25.7, 14.2, 6.9, 5.3, 3.1 m
36.0, 20.0 m
Air temperature (dry-bulb)Ventilated thermocouple wet-and dry-bulb thermometer
Prede PFH-01
25.7, 20.0, 14.2, 8.9, 6.9, 5.3, 3.1, 1.0 m
36.0, 30.1, 25.6, 20.0, 16.0, 11.2, 6.0, 1.0 m
HumidityCapacitive hygrometer
Vaisala HMP-45D
25.7, 14.2,6.9,5.3,3.1m
Humidity (wet-bulb)Ventilated thermocouple wet-and dry-bulb thermometer
Prede PFH-01
25.7, 20.0, 14.2, 8.9, 6.9, 5.3, 3.1, 1.0 m
36.0, 30.1, 25.6, 20.0, 16.0, 11.2, 6.0, 1.0 m
Wind SpeedSAT (Young, MODEL85000)25.7
MAKINO AG-75025.7, 20.0, 14.2, 8.9, 6.9, 5.3, 3.1, 1.0 m
36.0, 30.1, 25.6, 20.0, 16.0, 11.2, 6.0, 1.0 m
Wind DirectionVector instruments W200P26.2m
Barometric PressureN/A-
Soil TemperatureThermocouple thermometer0.05, 0.12, 0.19, 0.26 m deep
Soil Heat FluxEKO, MF-810.02 m deep
Soil Water ContentTDR soil-moisture meter; HYDRA HYD-100.05, 0.12, 0.19,0.26 m deep
Snow DepthN/A-
Groundwater LevelN/A-
Rainfall DurationN/A-
PrecipitationTippingbucket rain gauge; 0.5mm/pulse10m, immediately above canopy surface, top of ecological observation tower
Data Logger
Sampling Period10sec
Averaging Period5min
RecorderEto electric, CADAC-2 and PC

Turbulence Fluctuation Method (Eddy Covariance Method)

SystemRidge tower: closed-path
Valley tower: open-path
Three-dimensional sonic
(Ridge & valley tower)
Sensor span0.2m
Level25.7, 36.1 m
Height from Canopy Surface> 10 m
Gas Analyzer
LI-COR LI-6262 (ridge tower) Distance between
gas intake and analyzer
approx. 30m
Height of intake25.7 m
Height from Canopy Surface> 10 m
Distance between
gas intake and analyzer
0.3 m
Gas Analyzer
LI-COR LI-7500 (valley tower) Level36.1 m
Height from Canopy Surface> 10 m
Distance between
gas intake and analyzer
0.3 m
Data Logger
Sampling MethodContinuous
Averaging Period0 sec
Sampling Frequency5Hz
Filters for AntialiasingAvailable
CutOff Frequency24 Hz
Recording RangeAll data
RecorderTEAC DR-M3
Flux Calculation
Calculation Period1800s
MethodDetrendingw, u, Ta, CO2, H2O
Coordinate rotationCorrected
Line AveragingNot-corrected
Sensor SeparationNot-corrected
Humidity Correction of Virtual TemperatureNot-corrected

Vertical profiling CO2 Concentration in Canopy

InstrumentsLI-COR LI-6262
Concentration of Calibration Gas0, 400ppm
Sampling10 sec
Sampling PeriodEvery 120 seconds at a level x 8 levels
Averaging Period10 sec
PurposeTo obtain the vertical profile of CO2 concentration inside and above canopy

Relaxed Eddy Accumulation (REA) Method

itemTrace gas flux

Water Balance

PrecipitationTippingbucket rain gauge (IKEDA RT-5)
10m in height
Outlet FlowFloat type water-level gauge (IKEDA ATR-105)
installed on the weir built in valley (catchment area 1.6ha)

Other Observation

MethodPhotosynthesis of sunny crown, transpiration rate, diurnal variation of stomatal conductance
InstrumentLI-COR LI-6400
Observation FrequencySeveral times a year, on the basis of typical air temperature and vapor pressure deficit
Soil Respiration
MethodAutomatic closed chamber method
Observation FrequencyContinuous
MethodLitter trap
Observation FrequencyOnce a month in defoliation period
MethodDiameter, height
Observation FrequencyEvery 5 years
Sap Flow
MethodHeat Pulse Method
Observation FrequencyContinuous


KOMINAMI Yuji, JOMURA Mayuko, ATAKA Mioko, TAMAI Koji, MIYAMA Takafumi(2012): Heterotrophic respiration causes seasonal hysteresis in soil respiration in a warm-temperate forest. Journal of Forest Research, 17(3):296-304.

JOMURA Mayuko, KOMINAMI Yuji, ATAKA Mioko(2012): Differences between coarse woody debris and leaf litter in the response of heterotrophic respiration to rainfall events. Journal of Forest Research, 17(3):305-311.

MAKITA Naoki, HIRANO Yasuhiro, DANNOURA Masako, KOMINAMI Yuji, MIZOGUCHI Takeo, ISHII Hiroaki, KANAZAWA Yoichi (2009): Fine root morphological traits determine variation in root respiration of Quercus serrata. Tree Physiology, 29(4):579-585

KOMINAMI Yuji, JOMURA Mayuko, DANNOURA Masako, GOTO Yoshiaki, TAMAI Koji, MIYAMA Takafumi, KANAZAWA Yoichi, KANEKO Shinji, OKUMURA Motonori, MISAWA Noriko, HAMADA Shogo, SASAKI Taizo, KIMURA Hitoshi, OHTANI Yoshikazu (2008): Biometric and eddy-covariance-based estimates of carbon balance for a warm-temperate mixed forest in Japan. Agricultural and Forest Meteorology, 148(5):723-737

KOMINAMI Yuji, MIYAMA Takafumi, TAMAI Koji, NOBUHIRO Tatsuhiko, GOTO Yoshiaki (2003): Characteristics of CO2 flux over a forest on complex topography. Tellus B, 55(3):313-321

DANNNOURA Masako, KOMINAMI Yuji, OGUMA Hiroyuki, KANAZAWA Yoichi (2008): The development of an optical scanner method for observation of plant root dynamics. Plant Root, 2:14-18

JOMURA Mayuko, KOMINAMI Yuji, DANNOURA Masako and KANAZAWA Yoichi (2008): Spatial variation in respiration from coarse woody debris in a temperate secondary broad-leaved forest in Japan. Forest Ecology and Management, 255(1):149-155

TAMAI Koji, KOMINAMI Yuji, MIYAMA Takafumi, GOTO Yoshiaki, OHTANI Yoshikazu (2008): Topographical Effects on Soil Respiration in a Decious Forest -The Case of Weathered Granite Region in Southern Kyoto Prefecture-. Journal of Agricultural Meteorology, 64(4):215-222

MIYAMA Takafumi, KOMINAMI Yuji, TAMAI Koji, GOTO Yoshiaki, Teruhiko Kawahara, JOMURA Mayuko, DANNOURA Masako (2006): Components and seasonal variation of nighttime total ecosystem respiration in a Japanese broadleaved secondary forest. Tellus B, 58(5):550-559

GOTO Yoshiaki, KOMINAMI Yuji, MIYAMA Takafumi,TAMAI Koji, KANAZAWA Yoichi (2003): Aboveground Biomass and Net Primary Production of a Broad-leaved Secondary Forest in the Southern Part of Kyoto Prefecture, Central Japan. Bulletin of the Forestry and Forest Products Research Institute, 2(2):115-147 [in Japanese with an English abstract]

Research Fund

- Major Facility Installation for Carbon Dioxide Monitoring, Forestry Agency, MAFF*

- Research Grant, FFPRI

- Research Fund (Evaluation, Adaptation and Mitigation of Global Warming in Agriculture, Forestry and Fisheries: Research and Development), MAFF*

- Grant in Aid of Special Coordination Funds for Promoting Science and Technology, MEXT**

- Grant-in-Aid for Scientific Research, MEXT**

- Global Environment Research Account for National Institutes, MOE***

* MAFF: Ministry of Agriculture, Forestry and Fisheries of Japan
** MEXT: Ministry of Education, Culture, Sports, Science and Technology
*** MOE: Ministry of the Environment



Cooperative Researchers

Susumu TOHNO, Motonori OKUMURA, Masako DANNNOURA, Mioko ATAKA (Kyoto Univ.), Naoki MAKITA, Akira MATSUMOTO, Kenichi YOSHIMURA (Kobe Univ.), Mayuko JOMURA (Nihon University)

Contact Information

Forest Environment Group, Kansai Research Center,
Forestry and Forest Products Research Institute (FFPRI)
Address: 68 Nagaikyutaroh, Momoyama, Fushimi, Kyoto, 612-0855 JAPAN
TEL: +81-75-611-1201 (main)