Rubberflux is a flux tower site aiming at providing a complete picture of CO2, water and energy budget of a rubber tree plantation using the eddy-covariance (EC) method combined with ground-based measurements of carbon/water stocks and flux among the different components of the ecosystem. This approach allows quantifying flux (NEE an ETR), partitioning them among tree organs, soil, understorey vegetation (etc.…), and eventually understanding the interactions with climate and the availability of soil resources (water, nutrients). This is a common approach to 3 other flux tower sites on tropical tree plantations managed by CIRAD’s researchers within the umbrella of the SOERE F-ORE-T network. The Rubberflux site is located in Thailand, about 140km east of Bangkok. It was set-up in 2006 in a 12 years rubber plantation of the Chachoengsao Rubber Research Centre (CRRC), a research facility of the Rubber Research Institute of Thailand (RRIT). The collaboration with CRRC staff has also permitted to implement studies on a chronosequence of rubber plantations. A CIRAD’s researcher has been permanently based in Thailand since then to ensure the functioning of the site in collaboration with the staff of CRRC and a research team from Kasetsart University (KU). The research works conducted on the Rubberflux site have been funded by CIRAD and KU with substantial contribution of the Thai Research Fund (TRF), the SOERE FORET and the French Embassy in Thailand.

The Itatinga site is a long-term experimentation (started in 2008) that focus mainly on eucalyptus plantations. Our specific objectives are: - To understand the biogeochemical functioning of these fast-growing Eucalyptus plantations, and in particular the coupling between water, carbon, and nutrients cycles; - To use this information to develop eco-physiological models simulating the growth and balance of water, carbon and mineral elements of plantations; - To spatialize models from ground maps, satellite images and meteorological data; - To evaluate the environmental impacts and sustainability of plantations (impacts on water resources, soil fertility, regional climate. The experiment is located in Brazil, in the state of Sao Paulo. It is located at an average altitude of 800 m. Longitude / latitude 48°43'40.60''W / 22°58'4.50 ''S with an average annual temperature of 19.6 ° C and rainfall of the order of 1350 mm/year. The soil of the experiment is a ferralsol made of 72% sand, 15% clay, 3% silt. The site equipment includes a flux tower in a clonal Eucalyptus plantation, where nutrient cycles are also monitored. It also includes clonal tests, experimental plots that aim to study the effects of partial exclusion of rainfall and potassium fertilization on the cycles of mineral elements, carbon and water, and finally experimental plots comparing the ecophysiological / biogeochemical functioning of monospecific and plurispecific plantations. This study of the impact of tree diversity on the functioning of forest ecosystems is conducted on high-growing exotic species (mixture of Eucalyptus grandis and Acacia mangium) and on native species of Mata Atlântica (biome in which is located the Itatinga site). themes : Biogeochemistry of forest plantations, Ecological intensification of tropical forest plantations.

The Estrées-Mons platform is dedicated to arable crops. It evaluates the effect of agricultural practices on C and N cycles in the soil-plant system and their interaction. Nitrate leaching, SOM evolution and GHG emissions (CO2, N2O) are monitored according to level of N intensification, crop residues export, soil tillage and legume frequency. The key issue is to understand how the wide variation in C and N inputs affects C and N cycles in more or less intensified systems.

The Lusignan platform is dedicated to temporary grassland. It has been designed to increase our understanding of the effects of management of mixed arable crops / grasslands systems on the environmental outputs. The main scientific issue concerns the effects of grassland duration and management on SOM dynamics (quantity and composition), GHG emissions (CO2, N2O), nutrient lixiviation and functional biodiversity.

The site of Montiers, localized at the boundaries between Meuse and Haute-Marne departments, North-East of France, has a large surface area (143 ha). It comprises two soil successions (toposequence) and the climate, stand conditions (age, species, forest management) are equivalent on all the surface of the site. The facility comprises three biogeochemical stations of 10 000 m2 each and one flux tower above forest canopy (45 m-high) settled along a soil succession representative of soils of the region. The three stations include four substations of which three are strongly equipped and one is free for future experimentations. Each equipped substation comprises lysimeters at different soil depths (litter, -10 cm, -30 cm, -60 cm and -90 cm; 3 replicates in general), tensio-lysimeters (-10 cm, -30 cm, -60 cm, -90 cm and -120 cm; 3 replicates in general) and temperature and moisture probes at different soil depths (-10 cm, -30 cm, -60 cm and -90 cm; 4 replicates), litterbags (6 replicates), stemflows (6 replicates), gutters (4 replicates). These stations allow to follow-up on the long term the flows of water, and major (Ca, Mg, K, Na, P, Fe, Mn, Si, Al, S, C, N) and trace (Cl, Se, B, I, Cs) elements between the different compartments (soil, tree, atmosphere) of a beech forest. Each station is settled on a different soil type, i.e., alocrisol, calci-brunisol, rendosol thus allowing to assess the impact of the soil type on biogeochemical cycles and on tree growth. The flux tower is equipped with a Eddy Covariance system (CO2, H2O, and sensible heat) and a complete set of sensors recording the aerial and edaphic meterological conditions, the phenology and the canopy status. The data from flux tower are available on demand. The forest mainly consists in a beech timber of about 50 years: dominant species and forestry in the region. The effect of the soil on the biogeochemical and biological functioning of this beech forest is dealt with a very integrated approach (ecophysiology, microbiology, soil science and biogeochemistry). In addition, the flux tower permits to measure, at various levels of the canopy and above, meteorological parameters (temperature, radiation, and precipitation), the gaseous exchanges and the particular deposits.