Soil warning and rainfall exclusion

The precise prediction of the impact of climate change on biodiversity and the functioning of forest ecosystems can be challenging, as two components of climate change (reduced precipitation and increased temperatures) can act simultaneously (i.e., synergistically) or oppositely (i.e., antagonistically). This project is being conducted jointly by the in situ experimental platforms of AnaEE-France in Puéchabon, OH3P, and Font-Blanche. Its goal is to deploy an in situ system combining soil warming and rainfall exclusion uniformly across the platforms.

The experimental setup includes four treatments (control, rainfall exclusion, warming, and rainfall exclusion + warming), each replicated three times (3 replication blocks), for a total of 12 plots of approximately 5 m² each. The setup is installed in the forest understory and enables manipulation of soil moisture and temperature within the top 10 centimeters.

The scientific objectives of such ecosystem manipulation are to observe the effects of anticipated climate changes in the Mediterranean region on biodiversity and the functioning of forest soils.

The scientific consortium plans to specifically study changes in:

• the diversity and abundance of soil microorganisms and fauna,
• the biological activity of these organisms,
• the chemical composition of the soil,
• carbon fluxes associated with soil respiration and the emissions of volatile organic compounds.
  
  

The regulation system implemented ensures that the temperature in the heated soil is maintained at 2°C above the reference soil temperature. The plots were selected based on the results of soil chemical analyses and the measured LAI (Leaf Area Index).

From a scientific perspective, this project enables the AnaEE-France infrastructure to offer a new experimental setup for studying the responses of soil biodiversity, soil respiration and carbon sequestration, litter decomposition processes, and other biogeochemical soil functions of interest to the scientific community under warming and drought conditions.

The detailed spatial characterization of soil chemistry and biology on both platforms, required to establish the baseline conditions for the experimental treatments, will also contribute to enriching the AnaEE-France databases.

Continuous measurements.

Discrete measurements.

• LAI
• Micro-fauna
• Mycorhize
• Litterbag