Located in the French Pyrenees, the Metatron comprises 48 units, each stretches 100-m² * 2-m height, where we can manipulate climatic conditions (temperature, humidity or solar radiation). Units are connected by corridors allowing migration from one environment to another. The Metatron focuses on climatic effects on population dynamics, especially in the framework of the global warming and fragmentation.

The site comprises three distincts experimental set-ups: (1) a long-term (>10 years) partial throughfall exclusion experiment replicated three times and crossed with a thinning (-30% basal area) experiment aimed at simulating long-term precipitation decrease in accordance with climate change scenario for the Mediterranean area (-30% of precipitation), (2) a total rainfall exclusion experiment using a mobile roof has been set up to simulate extreme drought events and modify precipitation seasonality, and (3) an eddy-covariance flux tower running continuously since 2001 to measure seasonal variations in ecosystem functioning and year-to-year flux responses to drought and climate.