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Hainich National Park


Beech dominated decidious forest (unmanaged)
Tree height about 33 m

Latitude 51,07
Longitude 10,45
Elevation 439 m a.s.l.


  • From 1999 to present
  • Operated in collaboration with the University of Göttingen since 2011
  • Eddy covariance
  • Meteorology
  • Sap flow
  • Tree growth
  • Litter
  • Tree temperature
  • Soil moisture
  • Soil temperature


Description, History

The station exists since 1999 and is located in the National Park Hainich, near the city of Eisenach in Central Germany. The Hainich National Park was established in 1997 to protect one of the largest beech forests in Central Europe and covers an area of about 7600 ha.

The forest is dominated by beech (Fagus sylvatica, 65%), ash (Fraxinus excelsior, 25%) and maple (Acer pseudoplantanus and Acer plantanoides, 7%), with some European hornbeam (Carpinus betulus), elm (Ulmus glabra) and other deciduous species interspersed.

The tower is situated in the so called “Core zone” in the Weberstädter Holz. The Hainich National Park is the biggest beach tree area of Europe and was military area before Germany was reunited.

There is no human inference in the core of the Hainich National Park. Today the station is only accessible by walking; bigger transports are carried out by the Park rangers with a crawler vehicle.

Until 2010 a solar station for independent power supply was located on a clearing in a distance of 800 m from the flux tower. The solar panels were carried by a wooden construction. The batteries and a generator running on propane were sitting in an old foresters trailer below the solar panels. The generator needed to run only in wintertime to recharge the batteries.

Since May 2010 the station receives energy via 230 V line power cable. In 2011 the solar station was dismantled.

Precipitation and diffuse solar radiation are still being measured on the clearing.

The flux tower has a height of 45 m and exceeds the treetops by approx. 10 m.

Since 2011 the Hainich tower is operated by Prof. Dr. Alexander Knohl and his group from the University of Göttingen.

Variables & Instruments


  • Eddy covariance - CO2, water vapor, momentum, heat (Gill R3, LI6262)
  • Profile at 9 heights - CO2 (LI610)


  • Wind velocity and wind direction - 2D-ultrasonic-anemometer, Thies
  • Air pressure - pressure transmitter PTB101B, Vaisala
  • Air temperature and humidity - temperature-humidity-sensor KPC1_5-ME, Mela
  • Air temperature - ventilated thermometer Frankenberger, Friedrichs
  • Precipitation - heated tipping bucket rain gauge, Thies
  • Solar radiation - net radiometer CNR1, Kipp & Zonen
  • Terrestrial radiation - net radiometer CNR1, Kipp & Zonen
  • Photosynthetically active radiation - PAR sensor PAR Lite, Kipp & Zonen
  • Diffuse solar radiation - shadow ringed pyranometer CM11, Kipp & Zonen
  • Surface temperature - infrared thermometer KT15, Heitronics

Soil conditions

  • Soil temperature in 2 profiles having 7 depths - soil temperature sensors PT100, home-made
  • Soil moisture in 6 positions - soil moisture probes ML-2x, Delta-T
  • Soil heat flux in 5 locations - soil heat flux plates HP3/CN3, Rimco

Tree conditions

  • Tree trunk temperature in different depths - temperature sensors NTC, Campbell scientific
  • Tree growth - dendrometer WALDENDRO, home-made
  • Sap flow
  • Litterfall

Data acquisition

  • Meteorological data - datalogger CR23X, Campbell Scientific
  • CO2 profile data - datalogger CR10X, Campbell Scientific
  • Flux data - notebook
  • Vegetation - digital camera


Knohl A, Soee ARB, Kutsch WL, Gockede M, Buchmann N (2008) Representative estimates of soil and ecosystem respiration in an old beech forest. Plant and Soil. doi: 10.1007/s11104-007-9467-2

Knohl, A., Schulze, E.-D., Kolle, O., Buchmann, N. (2003). Large carbon uptake by an unmanaged 250-year-old deciduous forest in Central Germany. Agricultural and Forest Meteorology, 118(3-4), 151-167.

Herbst M, Mund M, Tamrakar R, Knohl A (2015). Differences in carbon uptake and water use between a managed and an unmanaged beech forest in central Germany. Forest Ecology and Management, 355, 101-108. doi: 10.1016/j.foreco.2015.05.034

Kutsch, W. L., Kolle, O., Rebmann, C., Knohl, A., Ziegler, W., Schulze, E. D. (2008). Advection and resulting CO2 exchange uncertainty in a tall forest in central Germany. Ecological Applications, 18(6), 1391-1405.

Schwarz, M. T., Bischoff, S., Blaser, S., Boch, S., Grassein, F., Klarner, B., Schmitt, B., Solly, E. F., Ammer, C., Michalzik, B., Schall, P., Scheu, S., Schöning, I., Schrumpf, M., Schulze, E. D., Siemens, J., Wilcke, W. (2016). Drivers of nitrogen leaching from organic layers in Central European beech forests. Plant and Soil, 403(1), 343-360. doi:10.1007/s11104-016-2798-0