Experimental approach

The integrated set of infrastructures in INCREASE provide a unique combination of opportunities namely:

  • Access to climate change experimental facilities in a network of shrubland sites across Europe to identify the potential impacts of climate change
  • Close proximity of laboratories to the field facilities with instruments and technical expertise required to support research into ecosystem structure and function and the impacts of climate change.


Figure 1. The location of the INCREASE infrastructures.

The field-based component of INCREASE is unique in combining experimental manipulations of climate factors with natural gradients - space-for-time substitution - thus allowing comparison of shrublands and their response to climate change using both the gradient and experimental approach.

In summary, we superimpose manipulations with water and temperature on existing gradients with respect to the same factors. Five of the sites have been running for 10-15 years.

The experiments provide three levels of information:

  • Between year data
  • Treatment data from climate manipulation
  • Across gradient data

Climate manipulation techniques

The experimental approach (Figure 2) significant improvement of past approaches due to the reduction in experimental artefacts (Beier et al. 2004, Ecosystems 7:583-597; Mikkelsen et al, Functional Ecology 2008).

INCREASE experimentally changes the climate in 20 m2 plots in the field at 6 European locations to simulate the climate change. The manipulations are:


Reflective curtains are drawn across the plots at night thus preventing heat loss. The curtains are controlled by a light sensor. In case of rain during the night, the curtains are withdrawn so the water balance is kept intact.


The plots are protected from rain by a rain cover for 1-2 months during the growing season. A rain sensor controls the curtains to ensure that they only cover the plots during rain events.

CO2 and interactive effects

The effects of CO2 alone and in combination with warming and drought is studied at a single site in Denmark. 











Figure 2. Climate manipulation techniques.