FHK:Fuji Hokuroku Flux Observation Site

General site detail (Updated 18 November 2019)
 Site name
 Fuji Hokuroku Flux Observation Site
 AsiaFlux site code
 FHK
 Location Fujiyoshida City, Yamanashi Pref, Japan
 Position 35º 26' 36.7"N, 138º 45' 53.0"E
 Elevation 1050-1150 m above sea level
 Slope 3-4 deg
 Terrain type
 Flat
 Area 150 ha
 Fetch N/A
 Climate Cfa:Temperate - mild with no dry season,
 hot summer
 Mean annual air temperature
 8.7 degC (2006-2012, at a height of 2m)
 Mean annual precipitation
 1844 mm (2006-2012)
 Vegetation type
 Deciduous needleleaf forest
 (Japanese larch afforestation)
 Domestic species (Overstory)
 Japanese larch (Larix Kaempferi Sarg.), evergreen
 needle-leafed species (Pinus densiflora and Abies
 homolepis), deciduous broad-leafed species (Swida
 controversa, Quercus serrata, Quercus crispula,
 Betula platyphylla var.japonica, Prunus incisa, etc.)
 Dominant species (Understory)
 Ferns (Dryopteris crassirhizoma, Dryopteris
 expansa), bamboo grass (Sasamorpha borealis),
 and other herbs.
 Canopy height
 20-26 m
 Age Around 70 years old (Planted around 1950)
 LAI Larch: 2.8 m2m-2 estimated based on the leaf
 mass abundance (Okano & Arase 2007), and
 2.4 m2m-2 estimated based on 3D portable laser
 scanner measurement (Maki et al., 2012),
 Understory: 3.0 m2m-2 (max)
 Soil type
 Coarse volcanic ash (Urakawa et al., 2015)

Observations
Eddy Covariance method (CO2)
 System Open- and closed-path systems (CO2 flux, latent heat flux)
 Wind speed 
 Three-dimensional sonic anemometer-thermometers:
 DA-600-3TV, Probe TR-61C, SONIC CORP.
                                      (Jan.1, 2006-  May 9, 2011),
 DA-650-3TV, Probe TR-61C, SONIC CORP.
                                      (May 9, 2011- Nov.22, 2011),
 DA-600-3TV, Probe TR-61C, SONIC CORP.
                                      (Nov.22, 2011- Apr.18, 2012),
 DA-700-3TV, Probe TR-61A, SONIC CORP.
                                      (Apr.18, 2012- Apr.11 2016)
 Air temperature
 Platinum resistance thermometer and capacitive hygrometer
 (HMP45A, Vaisala)
 Water vapor
 Open-path CO2/H2O analyzers, LI-7500, LI-COR
  (Jan.1, 2006- present)
 Closed-path CO2/H2O analyzers, LI-6262, LI-COR
  (Jan.1, 2006- Apr.11, 2016)
 Platinum resistance thermometer and capacitive hygrometer
  (HMP45A, Vaisala)
 CO2 Open-path CO2/H2O analyzer, LI-7500, LI-COR (Jan.1,
 2006- present), 
 Closed-path CO2/H2O analyzer, LI-6262, LI-COR (Jan.1,
 2006- Apr.11, 2016)
 Measurement height
 35 m
 Sampling frequency
 10 Hz
 Averaging time
 30 min
 Data logger
 DR-M3, TEAC, Japan (Jan.2006-March 2012),
 CR-23X, Campbell Scientific, USA (Jan.2006 - April 2008), 
 CR-3000, Campbell Scientific, USA (May 2008-)
 Data storage
 MO (TEAC); Data-logger CR-3000, Campbell Scientific, USA
 Original data
 Raw data

Meteorology
 Observation items
  Levels/ Depth
 Instrument 
 Global solar radiation
 (incoming)
 32 m,
 30 m
 Pyranometer (MS-402F, Eko,Japan),
 Radiometer (MR-50, Eko, Japan)
 Transmitted solar radiation
 (below canopy incoming)
 2 m (x5),
 2 m (x2)
 Pyranometer (MS-601, Eko, Japan),
 Radiometer (MR-50, Eko, Japan)
 Global solar radiation 
 (outgoing)
 30 m
 Radiometer (MR-50, Eko, Japan)
 Transmitted solar radiation
 (below canopy outgoing)
 2 m (x2)
 Radiometer (MR-50, Eko, Japan)
 Long-wave radiation
 (incoming) 
 30 m
 Radiometer (MR-50, Eko, Japan)
 Transmitted long-wave
 radiation (below canopy
 incoming)
 2 m (x2)
 Radiometer (MR-50, Eko, Japan)
 Long-wave radiation
 (outgoing)
 30 m
 Radiometer (MR-50, Eko, Japan)
 Transmitted long-wave
 radiation (below canopy 
 outgoing)
 2 m (x2)
 Radiometer (MR-50, Eko, Japan)
 Net radiation
 30 m, 2 m (x2) Radiometer (MR-50, Eko, Japan)
 PPFD (incoming)
 32 m
 Quantum sensor (ML-020P, Eko,
 Japan)
 Transmitted PAR
 (below canopy incoming)
 2 m (x5) Quantum sensor (LI-190S, LI-COR,  Jan.2006-Mar.2007), (ML-020P, Eko,  Japan, Mar.2007-)
 Reflected PAR (outgoing)
 30 m Qutantum sensor (LI-190S, LI-COR,
 Jan.2006-Aug.2008), (ML-020P,Eko,
 Japan, Sep.2008-)
 Reflected PAR
 (below canopy outgoing)
  2 m (x3)
 Quantum sensor (LI-190S, LI-COR,
 Jan.2006-Mar.2007), (ML-020P, Eko,
 Japan, Mar.2007-)
 Wind direction
 35 m Three-dimensional sonic
 anemometer-thermometers
 DA-600, Probe TR-61C (Jan.1, 2006-
 May 9, 2011); DA-650, Probe 
 TR-61C (May 9, 2011- Nov.22, 2011);
 DA-600, Probe TR-61C (Nov.22,2011
 -Apr.18, 2012); DA-700, Probe
 TR-61A (Apr.18, 2012-Apr.11, 2016),
 SONIC CORP.
  32, 27, 22, 16,
 10, 4.5, 2 m
 Sonic anemometer (MA-130A, Eko,
 Japan, Jan.2006-Mar.2007),
 (PGWS-100-3, GILL, Apr.2007-)
 Wind speed
 35 m Three-dimensional sonic
 anemometer-thermometers
 DA-600, Probe TR-61C (Jan.1, 2006-
 May 9, 2011); DA-650, Probe
 TR-61C (May 9, 2011- Nov.22, 2011);
 DA-600, Probe TR-61C (Nov.22,2011
 -Apr.18, 2012); DA-700, Probe
 TR-61A (Apr.18, 2012-Apr.11, 2016),
 SONIC CORP.
  32, 27, 22, 16,
 10, 4.5, 2 m
 Sonic anemometer (MA-130A, Eko,
 Japan, Jan.2006-Mar.2007),
 (PGWS-100-3, GILL, Apr.2007-)
 Air temperature
 32, 27, 22, 16,10,
 4.5, 2, 1, 0.5 m
 Platinum resistance thermometer
 and capacitive hygrometer
 (HMP-45D, Vaisala)
 Relative humidity 32, 27, 22, 16,
 10, 4.5, 2, 1,
 0.5 m
 Platinum resistance thermometer 
 and capacitive hygrometer
 (HMP-45D, Vaisala)
 Soil temperature
 0, 0.02,
 0.05 m (x3),
 0.15, 0.3, 0.6 m
 Platinum resistance thermometer 
 (C-PTWP, Climatec, Japan)
 Ground heat flux
 0.02 m (x3)
 Heat flux plate (PHF-01, REBS)
 Soil water content 
 0 m (x3),
 0.1, 0.2 m (x2)
 TDR sensor (CS616, Campbell)
 Barometric pressure
 1.5 m Barometer (PTB210, Vaisala)
 Precipitation 32 m Tipping-bucket rainguage with heater
 (CYG-52202, R. M. Young)
 Snow depth 2 m Sonic ranging sensor
 (SR50,Campbell)
 Spectral radiation(incoming)
 Global, direct/diffuse,
 transmitted
 32, 2 m Spectroradiometer (MS-700, Eko,
 Japan) and shadow band (32 m;
 PRB-100, PREDE, Japan)
 Spectral radiation reflected,
 transmitted (outgoing)
 30, 2 m Spectroradiometer (MS-700, Eko,
 Japan)
 COconcentration
 35, 32, 27, 22,
 16,10, 4.5, 2, 1, 
 0.5  m
 Closed-path CO2/H2O analyzer
 (LI-6262, LI-COR)

Fluxes of non-CO2 gases
 Gas
 CH4
 Method Hyperbolic relaxed eddy accumulation (HREA) method with
 a laser-based analyzer (GGA-24r-EP, Los GatosResearch
 Inc., USA), from Aug. 2011 to Sep. 2012 (Ueyama et al.,
 2013)
 Automated dynamic closed (non-steady-state through-flow)
 chambers with a laser-based analyzer (GGE-24r-EP), from
 Oct. 2012 (Ueyama et al., 2015)
 Measurement height
 35, 28, 18, 5, and 0.3m (HREA method), 0m (chambers)
 Data logger
 Laptop PC via serial communication
 Data storage
 -
 
Observation Period and Data Availability
 Measurement Period
 January 2006 to present
 Measurement Frequency
 Continuous
 Data Availability
 2006-2012 in AsiaFlux Database

Contact
 Nobuko Saigusa (n.saigusa [at] nies.go.jp)
 Center for Global Environmental Research (CGER),
 National Institute for  Environmental Studies (NIES)
 16-2 Onogawa, Tsukuba, Ibaraki 305-8506  JAPAN
 Tel : +81-29-850-2517   Fax : +81-29-858-2645
 http://db.cger.nies.go.jp/gem/moni-e/warm/flux/fuji.html
 [Flux and micrometeorology]
 Yoshiyuki Takahashi (yoshiyu [at] nies.go.jp)
 Center for Global Environmental Research (CGER),
 National Institute for  Environmental Studies (NIES)
 16-2 Onogawa, Tsukuba, Ibaraki 305-8506  JAPAN
 Tel : +81-29-850-2468   Fax : +81-29-858-2645
 [Soil respiration] Naishen Liang (liang [at] nies.go.jp), CGER/NIES
 Tel: +81-29-850-2774
 [Remote sensing] Hiroyuki Oguma (oguma [at] nies.go.jp),
 Reiko Ide CGER/NIES
 
Soil respiration
 Measurement method
 Automated dynamic closed chamber
 method (flow-through, non-steady-state
 design using IRGA and Integrated
 Cavity Output Spectroscopy
 (CH4/CO2))
 References for method
 Teramoto M., Liang N., Takahashi Y.,
 Zeng J., Saigusa N., Ide R., Zhao X.,
 2019: Enhanced understory carbon flux
 components and robustness of net
 CO2 exchange after thinning in a larch
 forest in central Japan. Agricultural and
 Forest Meteorology, 274, 106-117.
 Teramoto M., Liang N., Zeng J.,
 Saigusa N., Takahashi Y., 2017: Long-
 term chamber measurements reveal
 strong impacts of soil temperature on
 seasonal and inter-annual variation in
 understory CO2 fluxes in a Japanese
 larch (Larix kaempferi Sarg.) forest.
 Agricultural and Forest Meteorology,
 247, 194-206.
 Measuring system
 A24-channel automated chamber
 system (home-made by the
 investigator)
 IRGA
 Integrated Cavity Output
 Spectroscopy
 Li-820 (LI-COR), UGGA (LGR)
 Flow control
 High-precision flow transducer (FSM-V,
 CKD) and manual flow regulator
 Chamber type
 Clear PVC chamber
 Chamber size
 92cm in length × 90cm in width ×
 50cm in height (8 chambers for soil
 respiration and 8 chambers for
 heterotrophic respiration), and 90cm in
 length × 90cm in width × 100cm in
 height (8 chambers for net understory
 CO2 exchange).
 Number of chambers
 24
 Measuring intervals
 The maesurement period, during which
 the chamber lids were closed, was
 2.5min for each chamber (with data
 recorded at 10-s intervals using
 CR1000 datalogger (Campbell
 Scientific Inc.)) from 2006 to 2009.
 The meassurement period was 5.0min
 from 2010 on.
 Is the ground covered by snow
 in winter, how about the
 measurement on winter?
 Missing soil CO2 efflux data (gaps)
 during snow covered period were
 estimated based on Lloyd and Taylor
 equation for each chamber.
 Original data
 Raw data
 Air temperature collection
 Air temperature inside each chamber
 was measured using the home-made
 T-Type thermocouple.
 Soil temperature collection
 Soil temperature at the depth of 5-cm
 inside each chamber was measured
 using the home-made T-Type
 thermocouple.
 Air pressure collection
 Air pressure was measured using
 PX2760 (Omega Engineering)
 Understory PPFD collection
 6 sensors (SQ225; Apogee
 Instruments Inc.) at the height of 1m
 around plant chambers
 Soil moisture collection
 6 CS616 (Campbell Scientific Inc.)
 were used for monitoring soil moisture
 at the depth of 10cm in 6 randomly
 selected chambers (two chambers for
 each treatment).

Other
 Photosynthesis Occasionally 
 Ecological Investigation
 Tree heights, stand density, diameter,  biomass, LAI
 Phenology Continuous (photos)

Calibration Information
 Open-path analyzers were calibrated approximately every two months  with standard CO2 gases and a dew point generator (LI610, LI-COR).

 The gain of CO2 of the closed-path analyzers was checked once a day
 flowing two standard CO2 gases of 320 ppmv and 420 ppmv that were
 automatically controlled using a programmable data logger (CR23X
 during 2006-mid-2007 and CR3000 after that, both were made by, 
 Campbell Scientific, Logan, UT, USA.)







Infrastructure
 Tower (35m), Electrical power (AC), Internet communications is
 available.