Station d'Ecologie théorique et Expérimentale du CNRS à Moulis

Facility Metatron


Enclosed Ecosystem Platform

Parent institution: Centre National de la Recherche Scientifique
Active since 2010
Active through March to October

Fields of study

  • Climatology, Climate Change
  • Environmental sciences, Pollution
  • Terrestrial biology, Ecology

Contact Information

Cote, Julien

Guillaume, Olivier

This facility is located on the Commune of Caumont in Ariège (France) and has been operational since 2011. It comprises 48 habitats enclosed with insect-proof nets, each with a surface of 100-m² and a height of 2-m in which we can monitor and manipulate climatic conditions (temperature, humidity or solar radiation) thanks to shutters and sprinklers and manipulate species movements among units with corridors. Each enclosure acts as a mini ecosystem, with natural vegetation and insect communities and a relatively wide variety of thermal microhabitats (shaded, dense, and diverse vegetation, sun-battered rocks and logs, and ponds).

Diversity within these enclosed habitats is relatively high, with more than 140 plant species (~50 species per enclosure) and 123 invertebrate families (~40 invertebrate families per enclosure) found within the enclosures, compared to 134 plant species and 106 invertebrate families found in the nearby outside habitat. Enclosures can be connected by corridors which allow species to freely disperse from one unit to another.

The Location

Country: France

Latitude: +43 01 25.2

Longitude: + 1 05 34.5

Nearest town: Saint Girons 09200

Distance from neaerst town: 10 km

Relevant Research Questions

Predicting the consequences of climate change and landscape fragmentation on biodiversity and ecosystem functioning is a pressing challenge. However, uncertainties in these predictions remain large because most current empirical and theoretical studies 1) overlook the diversity of climate-change effects at all biological levels, from genes to ecosystems, and their intertwined nature and 2) investigate climate and fragmentation separately while they likely have interactive effects through modified species fluxes in the landscape. This incomplete vision hampers the development of effective mitigation strategies.

The Metatron allows the manipulation of climatic conditions and species movements in a set of wet grassland mesocosms hosting naturally diverse vegetation and invertebrate communities. This facility is therefore used to study the respective and interactive effects of climate warming and landscape fragmentation on all levels of biological organizations.


The climatic conditions in each enclosed habitat and the movements of species between habitats can be manipulated. This facility therefore allows to mimic simultaneously a climate change (e.g. temperature and/or humidity) and fragmented habitats and to study synergetic and antagonist effects of both elements of global change- interactions that are crucially needed for accurate predictions about global changes. Compared to lab warming experiment, the Metatron further provides semi-controlled environments with enclosures built on a wet grassland habitat with diverse and abundant vegetation hosting a self-maintaining invertebrate community. These semi-natural conditions permit the investigation of direct effects of climate and fragmentation (e.g. temperature-induce changes), the effects mediated by changes in species interactions (e.g. diet shifts, host-microorganism interactions) and therefore the ecological and evolutionary consequences of environmental changes.


The thermal regulation is done through a warming effect from the insect-proof nets and the shutters. The insect-proof nets create ~ 3 °C warmer conditions in the enclosed habitats than the outside. Motor-driven shutters allow reducing this warming effect and obtaining similar temperature than the outside. Our thermal manipulation is therefore dependent on the climatic conditions outside and cannot be heated to temperatures more than 3-4 °C than the outside. A system of sprinklers also allows watering enclosures and manipulating the humidity, but we do not have a drying system. Our human resources are also very limited and only allow to maintain the facility, but not to help for field work and data collecting.

Experimental Capabilities

Experimental Facilities

breeding facilities for birds, reptiles, amphibians, invertabrates and plants, controlled temperature fridges

Experiments duration: Weeks, Months, Years, Decades;

Experimental Aerea

Total area: 7000 m²

Available area: 7000 m²

Half is used by a local project until 2025

Experimental Unit Size

unit size: 100 m²

units interconnected by 1 corridor 10mx10mx2m populations cages 19m x 0.75 corridors


Replicates number: 48

Temporary storage

  • Dark room
  • Drying oven
  • Freezer
  • Liquid N
  • Refrigerator
  • Other

Available Instruments

  • respirometer
  • performance measure
  • HPLC
  • Gas chromatograph
  • cell counters
  • RMI
  • Ultrasounds echograph
  • Cytometer
  • Aviaries
  • Greenhouses

Electricity available on site.

Distance from Laboratory facilities


Years measured:


Mean Temperature: 12 °C

February Mean Temperature: 5.1 °C

July Mean Temperature: 20.2 °C


Mean Annual Speed: m/s

Max. Annual Speed: m/s

Dominant Direction:


Precipitation type: Rain;

Total annual precipitation: 772 mm

Mean snow cover duration: 0 days

State Variables

Continuously Measured

  • Air humidity
  • Air temperature
  • Other
  • light automatic&continuously measured in lux

Spot Measured

  • Soil temperature
  • Soil water content
  • Species richness
  • Population densities

Environmental Pressures

Variable Ecosystem Status
Warming Grassland Active
Precip Grassland Active
Hydro Grassland Active
Habitatfrag Grassland Active
Warming Wetland Active
Precip Wetland Active
Hydro Wetland Active
Habitatfrag Wetland Active

On site Staff and Accomodation

Peak season staff

Up to 65 people

Off season staff

Up to 65 people

Visiting personnel

No visitors allowed.

Bedrooms available

Up to 28 beds

Showers on site

Showers on site

Laundry on site

Laundry on site