Open-air Platform

Parent institution: CNRS
Active since 2003
Active through Continuous since 2003

Co-located with

  • ICOS

Fields of study

  • Terrestrial biology, Ecology

Contact Information

Limousin, Jean-marc
email: jean-marc.limousin@cefe.cnrs.fr

The site comprises three distincts experimental set-ups:

(1) a long-term (>15 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.

The Location

Country: France

Latitude: 43.74138889

Longitude: 3.59583333

Nearest town: Puéchabon

Distance from neaerst town: 4 km

Relevant Research Questions

Climate change impact on forest vulnerability, drought-induced tree mortality, carbon and water balance of Mediterranean ecosystems, forest management practices for mitigating climate change.


The site is within a typical Mediterranean ecosystem and climate. It has a long record of climatic data and forestry inventory (since 1984). The partial throughfall exclusion is among the world's longest continuously running ecosystem manipulation experiment in a forested ecosystem. The complementarity of the three experiments allows for studying the ecosystem response to changing climate at very different time scales from seasonal to decadal.


Around 500 automatic sensors are already running on the site creating a huge demand for human resources for calibrating, servicing and upgrading the set-up. The plot size of the total rainfall exclusion experiment could be increased to include more trees and reduce the edge effects. In addition, infra-red heaters could be installed under the moving roof to simulate heat waves in addition to extreme drought. The experimental site has so far only focused on the dominant species Quercus ilex, and increasing the number of sensors would allow the study of other less common species also present on site.

Experimental Capabilities

Experimental Facilities

Greenhouses are available at the lab (40 km away)

Experiments duration: Years;

Experimental Aerea

Total area: 1800 m²

1200 m² for the partial throughfall exclusion experiment 600 m² for the total rainfall exclusion experiment. The total site area is 50 ha.

Available area: 100000 m²

Experimental Unit Size

unit size: 100 m²

100 m² for partial rainfall exclusion, 180 m² for total rainfall exclusion


Replicates number: 3

3 replicates for the partial throughfall exclusion experiment 1 replicate for the total rainfall exclusion experiment

Temporary storage

  • Drying oven
  • Liquid N
  • Refrigerator
  • Freezer

Available Instruments

  • Licor 6400 photosynthesis system
  • Licor LAI 2200 LAI-meter
  • Pressure bomb PMS

Electricity available on site.

Distance from Laboratory facilities


Years measured: 17


Mean Temperature: 13.2 °C

February Mean Temperature: 6.6 °C

July Mean Temperature: 22 °C


Mean Annual Speed: 2.6 m/s

Max. Annual Speed: m/s

Dominant Direction: sector 337.5°-22.5°:21.5%; sector 22.5°-67.5°:21.3% ; sector 292.5-337.5°:22.5%


Precipitation type: Rain;

Total annual precipitation: 914.5 mm

Mean snow cover duration: days

Soil Types

State Variables

Continuously Measured

  • Air humidity
  • Air temperature
  • Atmospheric pressure
  • Canopy temperature
  • Incident PAR
  • Incident shortwave radiation
  • Soil temperature
  • Soil water content

Spot Measured

  • Fluorescence
  • Phenology
  • Population densities
  • Species richness

Environmental Pressures

Variable Ecosystem Status
Warming Forest Planned
Precip Forest Active
Management - other Forest Active

On site Staff and Accomodation

Peak season staff

Up to 2 people

Off season staff

Up to 2 people

Visiting personnel

Up to 2 visitors

No beds on site

No showers on site

No laundry on site