Open-air Platform

Parent institution: University of Copenhagen
Active since 2005
Active through 2005-current

Fields of study

  • Atmospheric chemistry and physics
  • Isotopic chemistry
  • Climatology, Climate Change
  • Environmental sciences, Pollution
  • Soil science
  • Hydrology
  • Terrestrial biology, Ecology

Contact Information

Larsen, Klaus Steenberg

In a dry heathland on sandy soil with vegetation dominated by Calluna vulgaris and Deschampsia flexuosa, the experimental facility aims to simulate future climate change using state-of-the-art manipulation techniques combined with state-of-the-art, automated measurement techniques. The facility builts upon the former CLIMAITE experiment - from 2005-2013 a full-factorial manipulation of the climate parameters CO2 (increased to 510 ppm in a FACE setup), temperature (+1 to 2 degrees by passive nighttime warming using curtains) and summer drought (separate curtains). With six replicates it gives a total of 48 plots. The setup consists of 12 rings in pairs of two = 6 blocks. Each ring is 6.8 meters in diameter and is divided into 4 plots adding to a total of 48 plots. For each pair of rings, one is a FACE ring with CO2 addition while one has ambient CO2 concentration. FACE and nighttime warming was initiated 3/10/2005. For further details refer to Mikkelsen et al (2008) Functional Ecology 22:185-195.

The new suggested setup will use half the existing blocks employing three treatment levels of drought from moderate to extreme levels (I-III) combined with elevated CO2 (+130 ppm = 530 ppm) in a FACE (Free Air CO2 Enrichment) setup thus providing a response surface approach. Warming treatments are not currently planned to be continued for budget reasons. The remaining 6 blocks will be available for future experiments and long term monitoring. In addition, subplots in the new setup will be harvested completely to study the long-term effects of climate treatments on regeneration of plant species.

The Location

Country: Denmark

Latitude: 55.8833333

Longitude: 11.9666667

Nearest town: Jægerspris

Distance from neaerst town: 5 km

Relevant Research Questions

The former and future experimental setups addresses key questions of ecosystem functioning under future climate scenarios. Questions include: a) What are the effects of climate change on carbon and nutrient turnover in the ecosystem? b) Will the ecosystem be a sink or a source of carbon under future climate scenarios? c) Will progressive nitrogen limitation play a role in the long-term carbon pool response to elevated CO2? d) Will future climate change affect biodiversity of plants and soil organisms and lead to community changes? e) Will there be significant interactions between different climate change factors?


The experimental facility is one of only a handful of experiments worldwide where the three major climate change factors (CO2, warming and precipitation change) have been manipulated simultaneously in situ in an ecosystem in all possible combinations (2005-2013). The facility has two well-equipped meteorological stations and all 48 existing plots are extensively equipped with various sensors (soil temperatures in 3 depths, soil water content in two depths, CO2 concentrations, soil water extraction via suction cups, minirhizotrons etc.). The facility offers a unique opportunity to add new experiments building on the 9 years of existing data. During 2009-2013 the site offered more than 1500 scientific user days, of which > 300 were international scientists visiting the facility. The research questions which may be addressed at the facility are highly relevant for AnaEE, i.e. ecosystem services like carbon storage under future climate, changes in biodiversity and species adaptation under climate change.


The major limitation is the plot size of about 10 m2 being relatively small and thus limiting the use of disruptive measurements (biomass harvest, soil coring etc.) However, there are good opportunities for additional new experiments that may be setup outside the existing plots. Furthermore, currently 24 of the 48 original plots are available for additional new experiments where the possibility of disruptive measurements exist.

Experimental Capabilities

Experimental Facilities

Various growth/climate chambers at University of Copenhagen or Technical University of Denmark may be used to complement experiments in the field. Both these facilities are proposed as part of the Danish AnaEE contribution.

Experiments duration: Weeks, Months, Years, Decades;

Experimental Aerea

Total area: 2500 m²

Total area of the site is 10000 m2. Approximately 2500 m2 could be used for experiments.

Available area: 2000 m²

Experimental Unit Size

unit size: 10 m²

10 m2 are the existing plots. Subplots of smaller size may be possible inside as well as outside existing plots.


Replicates number: 6

48 plots with six replicates of all treatment combinations was the previous setup (2005-2013). The planned new setup consists of 24 plots and in principle 3 replicates. However, the new setup is a response surface approach where all 24 plots are to be investigated together using a regression approach.

Cross-Ecosystem Manipulation

Grassland-heathland boundaries and potentially the transition to forest may be examined at the site

Manipulation Techniques

Elevated CO2: Free Air CO2 Enrichment (2005-2013 - no longer active) Precipitation change: Previously: Retractable curtains. Currently: Permanent rainout shelters. Warming: Not currently planned but previously by retractable nighttime warming curtains.

Temporary storage

  • Other
  • Drying oven
  • Freeze drier
  • Freezer
  • Liquid N
  • Refrigerator

Available Instruments

  • LICOR8100 (soil respiration)
  • LICOR6400 (Leaf leavel gas exchange)
  • Thetaprobes (Soil water content)
  • Temperature sensors
  • NDVI spectrosense
  • SPAD 502 (Minolta)
  • Handy PEA (Hansatech)
  • Mini-rhizotron scanner
  • PAR sensor

Electricity available on site.

Distance from Laboratory facilities


Years measured: 14


Mean Temperature: 9.5 °C

February Mean Temperature: 1 °C

July Mean Temperature: 19 °C


Mean Annual Speed: 2.2 m/s

Max. Annual Speed: m/s

Dominant Direction: west


Precipitation type: Both;

Total annual precipitation: 742 mm

Mean snow cover duration: days

Soil Types

State Variables

Continuously Measured

  • Air humidity
  • Air temperature
  • Atmospheric pressure
  • Incident PAR
  • Soil temperature
  • Soil water content
  • wind speed and direction, precipitation and CO2 concentration

Spot Measured

  • (aquatic) Nutrient levels
  • (aquatic) pH
  • Fluorescence
  • Phenology
  • Population densities
  • Species richness

Environmental Pressures

Variable Ecosystem Status
Precip Grassland Active
Management - Nutrients (levels or nutrient type) Grassland Planned
Management - grazing Grassland Planned
Management - species and/or ecotype combinations Grassland Planned
Precip Shrubland Active

On site Staff and Accomodation

Peak season staff

No on-site staff.

Off season staff

No on-site staff.

Visiting personnel

Up to 20 visitors

No beds on site

No showers on site

No laundry on site