Risø Environmenral Risk Assesment Facility


Enclosed Ecosystem Platform

Parent institution: Technical university of Denmark
Active since 1992
Active through all year

Co-located with

  • ICOS

Fields of study

  • Climatology, Climate Change
  • Environmental sciences, Pollution
  • Soil science

Contact Information

Mikkelsen, Teis Nørgaard

RERAF is a unique plant growth facility belonging to a new generation of phytotrons. Plant and microbial populations, communities, and model ecosystems can be studied under climate conditions ranging from subarctic to tropical. RERAF is built to support 6 large chambers, each 75 m3, that individually can be controlled with respect to temperature, Relative humidity, light (Max 400 micromol photons m-2 s-1), CO2 concentration in air (ambient to 990 ppm) and ozone (up to 199 ppb).

The Location

Country: Denmark

Latitude: 55.68369444

Longitude: 12.08486

Nearest town: Roskilde

Distance from neaerst town: 6 km

Relevant Research Questions

We have the possibility to investigate effects of climate change and air pollution on vegetation, soil and small ecosystems. Food security issues with respect to effects of single environmental factors and combinations can be investigated and replicated with a high accuracy for a high number of different crops. We can mimic the following environmental parameters:CO2, O3, day lengths, air temperature, air humidity, soil temperature and soil water as predicted in current and future scenarios from all over world.


RERAF is unique in the world because:

  1. Climate can be completely and accurately controlled for many parameters including CO2 and ozone. 
  2. It has both above- and possibilities for below-ground compartments.
  3. It is gas tight.
  4. chambers are relatively large (4m*6m*3m, width*length*height, 75 m3).


1) Light system causes limitation at the facility. The current light system is based on different types of incandescent lamps and delivers up to 400 µmol m-2 s-1 (PAR). Unfortunately it is very energy consuming and the light distribution is in addition heterogeneous. We propose to exchange the light system in all six chambers with a LED system. This will improve the spectral quality (closer to natural condition) , save energy, generate a more uniform light distribution, increase possible max light levels (up to 600 µmol m-2 s-1 (PAR)) and open up for individual control of lamps with respect to dimming the light levels.

2) The current database is very comprehensive and stores a lot of measures with respect to the machinery behind the Phytotron with a high time resolution. The database need currently to be restructured for easy access to the environmental data in chambers. In addition, it is preferable that supplementary sensors can be added on demands from each individual experiment and for this extra PLC modules shall be installed and a reprogramming is necessary.

3) Lacking staff- We are lacking funds for management and a full time technician is also needed.

Experimental Capabilities

Experimental Facilities

Field FACE facility (4 CO2 rings & 4 controls) Alder and willow crops with a high level of instrumentation.

Experiments duration: Months, Weeks, Years;

Experimental Aerea

Total area: 144 m²

6 chambers each 24m2

Available area: 144 m²

6 chambers each 24m2

Experimental Unit Size

unit size: 24 m²


Replicates number: 6

Temporary storage

  • Dark room
  • Drying oven
  • Freezer
  • Refrigerator
  • Other

Available Instruments

  • Li-COR 6400 including leaf chamber
  • Wescor water potential (osmotic)
  • Stomatal conduction (Decagon, SC1)
  • Soil water content & temp (Decagon sensors)
  • Campbell CR1000 dataloggers
  • SPAD 502 (Minolta)
  • Handy PEA (Hansatech)

Electricity available on site.

Distance from Laboratory facilities


Years measured:


Mean Temperature: °C

February Mean Temperature: °C

July Mean Temperature: °C


Mean Annual Speed: m/s

Max. Annual Speed: m/s

Dominant Direction:


Total annual precipitation: mm

Mean snow cover duration: 0 days

State Variables

Continuously Measured

  • Air humidity
  • Air temperature
  • Incident PAR

Spot Measured

  • Canopy temperature
  • Fluorescence
  • Phenology
  • Population densities
  • Soil temperature
  • Soil water content
  • Species richness

Environmental Pressures

Variable Ecosystem Status
CO2 Agrosystem Active
Warming Agrosystem Active
Precip Agrosystem Active
Hydro Agrosystem Active
Airpoll Agrosystem Active
Management - Nutrients (levels or nutrient type) Agrosystem Active
CO2 Grassland Active
Warming Grassland Active
Precip Grassland Active
Hydro Grassland Active
Management - Nutrients (levels or nutrient type) Grassland Active
Airpoll Grassland Active
CO2 Shrubland Active
Hydro Shrubland Active
Airpoll Shrubland Active
Management - Nutrients (levels or nutrient type) Shrubland Active

On site Staff and Accomodation

Peak season staff

Up to 2 people

Off season staff

No on-site staff.

Visiting personnel

Up to 20 visitors

No beds on site

Showers on site

Showers on site

No laundry on site