Climate phytotron RERAF, DK

Site location and background
RERAF is a unique plant growth facility belonging to a new generation of phytotrons. RERAF (Risoe Environmental Risk Assessment Facility) consists of 6 large growth chambers for climate change and air pollution experiments, where the environmental conditions can be precisely controlled. The facility is placed approximately 40 km from Copenhagen at Risø DTU, Roskilde.

Climate change manipulations
RERAF is gas tight which allows for exposure of plants and model ecosystems to gaseous air pollutants. The phytotron is designed with a central control unit containing a row of six growth chambers. Each chamber is 4 x 6 m x 3.1 m (w*l*h) and is equipped with separate climate control and ventilation systems, which control the level of light, temperature and humidity.

The control systems are also capable of simulating the diurnal and annual cycle of many environmental parameters that are important drivers of plant growth (photosynthetically active radiation, temperature, CO2 concentration, O3 concentration, relative humidity). Short duration peak values can therefore be included in experiments and the effects of long-term transients can be studied.

Gases such as CO2 and O3 can be supplied separately or in combination to each chamber. The temperature in each chamber can be controlled between 5 °C and 40 °C and can be programmed to simulate diurnal or faster cycles. A computer controlled automatic water system distributes tap water to individual pots. Up to three different doses (1-99 litres * 1-5 times) a day can be delivered to the individual tables in each chamber.

Relative humidity in chambers is normally controlled within +/- 2%. Gas concentrations, temperature and RH in the chambers are monitored and adjusted continuously.

Presently, two multidisciplinary projects on effect of climate change to plant production are performed in RERAF. In the six chambers crop plants are exposed to different multi-factor and single-factor combinations of elevated [CO2], [O3] and temperature. The most extreme climate scenarios correspond to IPCCs predictions for the Nordic countries in year 2075 (700 ppm CO2, 24/19 C, 60-100 ppb O3).

The other growth conditions are designed to simulate a growth season, with a day length of 16 hours and a light intensity at 400-600 mol/m2/s (depending on the natural light). The relative humidity is 55% during the day and 70% at night.

The facility is open to other projects on effects of climate change to plants.

Read more about the present projects at

Research activities and research ideas
In RERAF the ongoing research focuses on three issues:

  • Effects to plants from multifactor manipulation of all four climate change factors: atmospheric CO2 and O3 concentrations, temperature and water.
  • Effects from multigenerational climate selection of plants (now 5 successive plant generations selected). Effects are analysed at the genome, transcriptome, protein and physiology level; ultimately plant fitness is measured.
  • Climate effects to plants infected with their present and expected future fungal diseases.

We would like to collaborate on environmental effects to plants, e.g. effects on key biochemical pathways like photosynthesis and plant fungal defence, effects on plant productivity and physiology, effects of drought stress, changes in genetic structure of populations, phenology and root development, mineral/element analysis, ultrastructure and secondary compounds.

The on-site team
The INCREASE on-site team for RERAF includes Rikke Bagger Jørgensen, Teis N. Mikkelsen, Georg Frenck and Claus Beier.

For more information
Please, contact Rikke Bagger Jørgensen email, Risoe DTU, Technical University of Denmark, Risø National Laboratory for Sustainable Energy, P.O. Box 49, Frederiksborgvej 399, 4000 Roskilde, Denmark.

Contact can also be made to Teis Mikkelsen - email ; same address as above.

The RERAF experiments are funded by the Risø DTU, Danish Research Council, Copenhagen University SCIENCE, and Aarhus University.

Door at RERAF